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By the Year

In 2026 there have been 95 vulnerabilities in Red Hat Single Sign On with an average score of 7.1 out of ten. Last year, in 2025 Red Hat Single Sign On had 11 security vulnerabilities published. That is, 84 more vulnerabilities have already been reported in 2026 as compared to last year. However, the average CVE base score of the vulnerabilities in 2026 is greater by 0.78.




Year Vulnerabilities Average Score
2026 95 7.13
2025 11 6.35
2024 30 6.38
2023 5 5.76

It may take a day or so for new Red Hat Single Sign On vulnerabilities to show up in the stats or in the list of recent security vulnerabilities. Additionally vulnerabilities may be tagged under a different product or component name.

Recent Red Hat Single Sign On Security Vulnerabilities

Keycloak role-users endpoint leaks user info due to missing admin permission
CVE-2026-17059 6.5 - Medium - July 24, 2026

A flaw was found in the role-users endpoint of the keycloak-services library, which is the core component of the Keycloak identity and access management solution. The issue occurs because the system fails to check if an administrator has permission to view individual users when listing members of a role. This allows a restricted administrator to see private information, such as names and email addresses, for users they should not be able to access.

Insecure Direct Object Reference / IDOR

Keycloak Admin REST API: View-Only Admins Can Leak Client Secrets
CVE-2026-17048 5.5 - Medium - July 24, 2026

A flaw was found in the Keycloak Admin REST API, which is used to manage security realms and clients. The issue occurs when the system processes requests for rotated client secrets that are stored in a secure vault. Due to improper boundary enforcement, a delegated administrator with view-only permissions can retrieve the actual resolved secret instead of the vault placeholder, leading to the exposure of sensitive credentials.

Information Disclosure

KeycloakServices auth endpoint leaks recaptcha keys via config VIEW only
CVE-2026-16104 4.3 - Medium - July 17, 2026

A flaw was found in the authentication configuration endpoint of the keycloak-services component, which is the core engine for Red Hat Build of Keycloak identity and access management. The issue occurs because the system fails to mask sensitive configuration values, such as reCAPTCHA secret keys, when they are requested by administrators with view-only permissions. This can lead to the exposure of third-party service credentials to unauthorized personnel or through administrative logs.

Insufficiently Protected Credentials

Brute-Force Token Redemption Loophole in Keycloak CIBA (keycloak-services)
CVE-2026-16103 4.3 - Medium - July 17, 2026

A flaw was found in the keycloak-services component of Keycloak. This issue is an incomplete fix for CVE-2026-9798, where brute-force protection checks were added to the Client-Initiated Backchannel Authentication (CIBA) initiation handler but were omitted from the token redemption handler. This allows an attacker with valid client credentials to obtain access and refresh tokens for a user account that has been locked due to brute-force protection, provided the authentication request was started before the lockout occurred and was approved by the user.

Improper Enforcement of Behavioral Workflow

Keycloak Admin API: RBAC Bypass Removing Composite Roles
CVE-2026-16106 4.9 - Medium - July 17, 2026

A flaw was found in the admin REST API of Keycloak, a solution for identity and access management. The issue occurs when a delegated administrator attempts to remove a child role from a composite role. Due to missing authorization checks, an attacker with limited administrative permissions can remove privileged roles they are not authorized to manage, leading to a loss of access for other users and administrators.

AuthZ

Keycloak Default-Group Disclosure via Delegated Admin
CVE-2026-16108 4.3 - Medium - July 17, 2026

A flaw was found in the default-groups REST endpoint and realm representation of Keycloak. This component is responsible for managing groups that are automatically assigned to new users within a realm. The issue allows a delegated administrator with realm-viewing permissions to see the names and identifiers of hidden default groups, even if they lack the specific permissions to view those groups. This can lead to the exposure of sensitive organizational structures or internal group names.

Information Disclosure

Bypass Keycloak Client Policies Signed JWT Enforcement
CVE-2026-16093 5.4 - Medium - July 17, 2026

Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs for authentication. A flaw was discovered where this enforcement can be bypassed. An attacker with valid client credentials can provide a fake, unsigned assertion header that tricks the system into thinking the policy requirements have been met. This allows the attacker to authenticate using simpler methods like a client secret even when the administrator has mandated more secure, signed assertions.

Reliance on Untrusted Inputs in a Security Decision

Keycloak Services OAuth 2.0 Code Binding Flaw (Red Hat)
CVE-2026-16089 5.4 - Medium - July 17, 2026

A flaw was found in the keycloak-services component of Red Hat Build of Keycloak. The issue occurs because OAuth 2.0 authorization codes are not properly bound to the client that originally requested them. An attacker who can intercept an authorization code can modify it to be redeemed by their own client, potentially allowing them to obtain access tokens for a victim's identity.

Session Fixation

Keycloak OrgMgmt API Bypass: Unauthorized Injection via Invitation Link
CVE-2026-16072 4.9 - Medium - July 17, 2026

A flaw was found in the organization management component of Keycloak. A delegated administrator with permission to manage organizations can create an invitation for a non-existent email address and then retrieve the secret registration link directly through the application programming interface. By using this link, the administrator can create new user accounts and add them to the organization without having the required user management permissions or access to the invited email account. This allows an administrator to bypass security boundaries and add unauthorized members to an organization.

Authorization

Keycloak keycloak-services: OIDC IDP Secret Leakage via Masked Client Secret
CVE-2026-15943 5.5 - Medium - July 17, 2026

A flaw was found in the Keycloak keycloak-services component, which handles the management of identity providers. The issue occurs when a delegated administrator updates an OIDC identity provider using a masked client secret sentinel value. Due to improper validation, Keycloak reuses the existing real secret even if security-sensitive fields like the token URL have been changed, allowing an attacker to redirect and capture the secret.

Improper Validation of Consistency within Input

Keycloak FGAP v2 Bypass: Delegated Admin Exposes Parent Group Data
CVE-2026-15945 4.3 - Medium - July 16, 2026

A flaw was found in the group search functionality of the Keycloak server's administrative API. When Fine-Grained Admin Permissions (FGAP) v2 is enabled, a delegated administrator can bypass access restrictions to view parent groups they are not authorized to see. By searching for a child group they have permission to view, the system incorrectly returns the full details of the parent group in the response, leading to the disclosure of sensitive group attributes and configuration.

Insecure Direct Object Reference / IDOR

CVE-2025-12799: XSS in Jastow (and Undertow) via unescaped URL chars
CVE-2025-12799 6.5 - Medium - July 07, 2026

A flaw was found in Jastow. Jastow is vulnerable to Cross-Site Scripting (XSS) attack. If using a set of combined configuration to allow unescaped characters in URL with embedded Undertow and Jastow, a server might be vulnerable to improper input handling.

XSS

Keycloak OIDC Broker Email-Verified Claim Bypass
CVE-2026-14781 4.8 - Medium - July 05, 2026

A flaw exists in the org.keycloak.broker.oidc package where the OIDC broker incorrectly synchronizes the email_verified claim. When an OIDC identity provider is configured with trustEmail=true and the userinfo endpoint is enabled, Keycloak retrieves the email address from the userinfo response but retrieves the email_verified status exclusively from the id_token. The root cause is a lack of validation ensuring that the email_verified claim in the id_token actually refers to the email address returned by the userinfo endpoint. If these two sources return different email addresses, the id_token's email_verified=true claim is blindly applied to the userinfo email. Exploitation Conditions: The OIDC identity provider must have trustEmail set to true (non-default). The userinfo endpoint must be enabled (default). The attacker must control or have compromised the upstream OIDC provider. Concrete Impact: Mark arbitrary email addresses as verified in the Keycloak database. Bypass email-based security controls or verification workflows. Potential account takeover if the application relies solely on the email_verified flag from the IdP to link accounts.

Improper Validation of Consistency within Input

Keycloak ClientResource Permission Bypass via FGAP v2
CVE-2026-14614 5.4 - Medium - July 03, 2026

A flaw was found in the ClientResource component of Keycloak's admin services when Fine-Grained Admin Permissions (FGAP) v2 is enabled. This issue allows a delegated administrator, who should only have limited control over specific clients, to attach or remove hidden client scopes that they are not authorized to see or manage. As a result, an attacker could inject unauthorized data or permissions into the security tokens issued to end-users, potentially tricking other applications into granting higher levels of access than intended.

Insecure Direct Object Reference / IDOR

Keycloak FGAP v2: Admin RLS Bypass Exposes Hidden Groups
CVE-2026-14613 4.3 - Medium - July 03, 2026

A vulnerability was discovered in Keycloak's administrative interface that allows certain administrators to see information about groups they shouldn't have access to. When the new Fine-Grained Admin Permissions (FGAP v2) are turned on, an administrator who is allowed to see a specific "role" can also see a list of all groups assigned to that role. The system fails to check if the administrator has permission to see those specific groups. This could allow a restricted administrator to discover "hidden" groups and see their details, such as internal names and custom settings, which might contain sensitive deployment information.

Authorization

Keycloak JWT Algorithm Confusion Bypass Via Authorization Grant
CVE-2026-11800 8.1 - High - June 25, 2026

A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an attacker with valid client credentials to bypass signature verification. By forging an assertion, the attacker can create unauthorized access tokens. This enables the attacker to impersonate any federated user linked to the affected Identity Provider, leading to unauthorized access and potential privilege escalation.

Improper Verification of Cryptographic Signature

Keycloak Policy Enforcer Auth Bypass via Access-Denied Page Injection
CVE-2026-9800 8.1 - High - June 25, 2026

A flaw was found in Keycloak Policy Enforcer. This vulnerability allows any authenticated user to bypass all authorization policies, including role, scope, and User-Managed Access (UMA) permission checks. By including the configured access-denied page path within a request URL, either as a path segment or a query parameter, an attacker can gain unauthorized access to protected resources.

Comparison Using Wrong Factors

AngularJS 1.2+ SCE Bypass Enables JS Execution
CVE-2026-11998 7.6 - High - June 24, 2026

A flaw in AngularJS' Strict Contextual Escaping (SCE) logic allows bypassing certain SCE policies for resource URLs and can lead to arbitrary JavaScript execution within the context of the victim's browser session. SCE's purpose is to ensure that only trusted or safe values are used in certain security-sensitive contexts, such as resource URLs, including URLs that define executable JavaScript scripts, '<iframe>' documents, route templates, etc. A flaw in the logic that tries to match entire URLs against regular expression matchers can result in partial matches for certain types of regular expressions, effectively bypassing the policies and allowing the use of unsafe values as resource URLs. This issue affects AngularJS versions greater than or equal to 1.2.0-rc.3. Note: The AngularJS project was already End-of-Life when this CVE was published and will not receive any updates to address this issue. For more information see the  End-of-Life announcement https://docs.angularjs.org/misc/version-support-status .

Incomplete Filtering of Special Elements

Jackson-Databind PTV Array Type Allowlist Bypass 2.10.0-2.18.8, 2.21.4, 3.1.4
CVE-2026-54513 8.1 - High - June 23, 2026

jackson-databind contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor. From 2.10.0 until 2.18.8, 2.21.4, and 3.1.4, BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() allowlists any array type based only on clazz.isArray(), without validating the array's component (element) type against the configured allowlist. A PTV built with allowIfSubTypeIsArray() plus an explicit concrete-type allowlist therefore still permits EvilType[] even though EvilType is not allowlisted. When Jackson deserializes the elements and no per-element type IDs are present, it instantiates the component type directly with no further PTV check, bypassing the allowlist. This vulnerability is fixed in 2.18.8, 2.21.4, and 3.1.4.

Denylist / Deny List

Netty OOM via RedisArrayAggregator pre-4.1.135/4.2.15
CVE-2026-50011 7.5 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, RedisArrayAggregator pre-allocates ArrayList with initial capacity equal to the RESP array element count declared in an array header. That count is taken from the wire before the corresponding child messages exist. A small malicious header can claim a huge initial capacity. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Resource Exhaustion

Netty 4.1/4.2 X509MT Wrapper Bug: No Hostname Verification
CVE-2026-50010 7.5 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, SimpleTrustManagerFactory.engineGetTrustManagers() and related paths wrap any user-supplied plain X509TrustManager in X509TrustManagerWrapper, which extends X509ExtendedTrustManager but implements the 3-arg checkServerTrusted(chain, authType, SSLEngine) by discarding the SSLEngine and calling the 2-arg delegate. Because the object now IS an X509ExtendedTrustManager, neither SunJSSE's internal AbstractTrustManagerWrapper nor Netty's own OpenSslX509TrustManagerWrapper will re-wrap it to add endpoint-identification. Consequently, even though Netty 4.2 sets endpointIdentificationAlgorithm="HTTPS" by default, a client built with `SslContextBuilder.forClient().trustManager(somePlainX509TrustManager)` performs no hostname verification at all. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Improper Verification of Cryptographic Signature

Netty <4.1.135 / <4.2.15 HAProxy PROXY v2 codec memory leak (PP2_TYPE_SSL)
CVE-2026-48059 7.5 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, the HAProxy PROXY protocol v2 codec in netty leaks native or heap memory on every connection when a client sends a syntactically valid header containing nested `PP2_TYPE_SSL` TLVs (type-length-value records) at depth two or greater. The leak occurs on the successful parse path no exception is thrown, the message fires downstream, the decoder removes itself, and the application releases the `HAProxyMessage` normally. Yet the underlying cumulation buffer (a pooled, potentially direct `ByteBuf` allocated by the channel) remains permanently pinned. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Memory Leak

Netty netty-codec-http2 HTTP2 Decompressor Resource Leak pre 4.1.135/4.2.15
CVE-2026-48043 7.5 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. In netty-codec-http2 prior to versions 4.1.135.Final and 4.2.15.Final, the `DelegatingDecompressorFrameListener` class orchestrates HTTP/2 decompression by embedding a per-stream `EmbeddedChannel` that runs the appropriate decompression codec (gzip, deflate, zstd) and forwards decompressed chunks to a wrapped listener. Each decompressed chunk is a pooled `ByteBuf` handed to an anonymous `ChannelInboundHandlerAdapter` tail handler, which becomes the sole owner responsible for releasing it. A remote peer could send frames that would result in the flow-controller throwing and so trigger a resource leak which at the end might take down the whole JVM due OOME. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Resource Exhaustion

Netty 4.1/4.2: RedisArrayAggregator DirectMemory Leak (Pre4.1.135/4.2.15)
CVE-2026-48006 7.5 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, the RedisArrayAggregator handler permanently leaks pooled direct-memory buffers when a Redis pipeline connection closes before a RESP array aggregate completes. The handler retains child messages in per-handler state (`depths` field) but defines no `channelInactive`, `handlerRemoved`, or `exceptionCaught` method to release them when the pipeline tears down. Because the leaked buffers are slices of `PooledByteBufAllocator` chunks, they prevent those chunks from being returned to the JVM-wide direct-memory pool. Repeated connection churn by any network peer monotonically drains this shared pool, eventually causing allocation failures on all Netty channels in the process. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Memory Leak

Netty <=4.2.15 DNS Cache Poisoning via DnsResolveContext
CVE-2026-47691 8.7 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's `DnsResolveContext` insufficiently validates the bailiwick of NS records, enabling DNS Cache Poisoning. An attacker controlling an authoritative name server for a subdomain can poison the cache for parent domains (like `.co.uk`). In `io.netty.resolver.dns.DnsResolveContext.AuthoritativeNameServerList#add` method accepts any NS record from the AUTHORITY section as long as the record's name is a suffix of the questionName. Subsequently, the `handleWithAdditional` method caches the associated A records from the ADDITIONAL section directly into the `authoritativeDnsServerCache` under the parent domain's key. This bypasses standard bailiwick rules, where a server authoritative for a subdomain should not be trusted to provide authoritative records for its parent. The poisoned cache is then used for all future resolutions under the parent domain's key. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Insufficient Verification of Data Authenticity

Netty DoS via unbounded CompositeByteBuf chain (4.1.135/4.2.15)
CVE-2026-46340 7.5 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. In versions of netty-transport-sctp prior to 4.1.135.Final and 4.2.15.Final, for each non-complete SctpMessage fragment the handler does `fragments.put(streamId, Unpooled.wrappedBuffer(frag, byteBuf))`, wrapping the previous accumulator and the new slice into a *new* CompositeByteBuf every time. After N fragments the accumulator is an N-deep chain of composites, each holding references and component arrays; readableBytes()/getBytes() on the final buffer recurse N levels. There is no limit on N, on total bytes, or on the number of streamIdentifiers an attacker can open (each gets its own map entry). A peer that never sets the `complete` flag can grow this structure indefinitely from tiny 1-byte DATA chunks. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Allocation of Resources Without Limits or Throttling

Netty DnsResolveContext CNAME Bailiwick Validation Flaw (before 4.1.135,4.2.15)
CVE-2026-45674 8.7 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's DnsResolveContext fails to validate the origin (bailiwick) of CNAME records in DNS responses. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Insufficient Verification of Data Authenticity

Netty <4.1.135 / <4.2.15 TLS ClientHello Buffer Overflow
CVE-2026-45416 7.5 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, SslClientHelloHandler.decode() reads the 24-bit TLS handshake length and, when the ClientHello does not fit in the first record, eagerly allocates `ctx.alloc().buffer(handshakeLength)` (line 161). The guard at line 140 is `handshakeLength > maxClientHelloLength && maxClientHelloLength != 0`, and the commonly-used SniHandler/AbstractSniHandler constructors (SniHandler(Mapping), SniHandler(AsyncMapping), AbstractSniHandler()) pass maxClientHelloLength=0 and handshakeTimeoutMillis=0, so the length guard is disabled and no timeout is scheduled. A 16 MiB request exceeds the default pooled chunk size and becomes a huge/unpooled allocation performed immediately. The buffer is retained in the handler until the channel closes. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Allocation of Resources Without Limits or Throttling

Netty netty-codec-haproxy 4.1.x/4.2.x Memory Leak via HAProxyMessage TLV
CVE-2026-44893 7.5 - High - June 12, 2026

Netty is a network application framework for development of protocol servers and clients. In netty-codec-haproxy prior to versions 4.1.135.Final and 4.2.15.Final, when decoding a PP2_TYPE_SSL TLV, HAProxyMessage.readNextTLV() first calls `header.retainedSlice(header.readerIndex(), length)` and only then reads the 1-byte client field and 4-byte verify field. If the attacker sets the TLV length below 5, the subsequent readByte/readInt throws IndexOutOfBoundsException. HAProxyMessageDecoder only catches HAProxyProtocolException around this call, so the IOOBE propagates and the retained slice on the pooled cumulation buffer is never released. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Improper Check or Handling of Exceptional Conditions

Apache CXF < 4.2.2 RCE via Untrusted JMS Config
CVE-2026-50632 8.8 - High - June 12, 2026

A further incomplete fix for a previous advisory CVE-2026-44417 (Untrusted JMS configuration can lead to RCE) for Apache CXF has been identified, which can allow code execution capabilities, if untrusted users are allowed to configure JMS for Apache CXF. Users are recommended to upgrade to versions 4.2.2 or 4.1.7, which fixes this issue.

Improper Input Validation

Apache CXF <4.2.2 OOB External Entity via SAXParserFactory
CVE-2026-49875 7.5 - High - June 12, 2026

Apache CXF's EndpointReferenceUtils and W3CMultiSchemaFactory classes construct a SAXParserFactory without the necessary JAXP hardening configurations, enabling out-of-band (OOB) external entity resolution. Users are recommended to upgrade to versions 4.2.2 or 4.1.7, which fix this issue.

XXE

Netty NetCodecRedis DoS pre4.1.135/4.2.15
CVE-2026-44890 7.5 - High - June 11, 2026

Netty is a network application framework for development of protocol servers and clients. In netty-codec-redis prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can cause DoS by sending crafted Redis payloads across multiple connections without `\r\n`. This exhausts the server's direct memory pool (OutOfDirectMemoryError), preventing legitimate connections from being processed. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Resource Exhaustion

Netty netty-codec-redis DoS via Deeply Nested Redis Arrays before 4.1.135/4.2.15
CVE-2026-44250 7.5 - High - June 11, 2026

Netty is a network application framework for development of protocol servers and clients. In netty-codec-redis prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can cause DoS by sending a crafted Redis payload with deeply nested arrays. This forces the server to allocate a massive number of state objects and collections, leading to memory exhaustion and an OutOfMemoryError. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Resource Exhaustion

Netty IpSubnetFilterRule IPv6 Bypass < 4.1.135/4.2.15
CVE-2026-44249 8.1 - High - June 11, 2026

Netty is a network application framework for development of protocol servers and clients. In netty-handler prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). Valid public IP addresses can bypass the restrictions. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Authorization

Apache CXF RCE via Untrusted JMS Config Fixed in 4.2.1/4.1.6/3.6.11
CVE-2026-44417 7.5 - High - May 22, 2026

The fix for CVE-2025-48913: Apache CXF: Untrusted JMS configuration can lead to RCE was not complete, meaning that another path in the code might lead to code execution capabilities, if untrusted users are allowed to configure JMS for Apache CXF. Users are recommended to upgrade to versions 4.2.1, 4.1.6 or 3.6.11, which fix this issue.

Improper Input Validation

Netty <4.2.13.Final/4.1.133.Final MQTT 5 Properties Buffering Resource Exhaustion
CVE-2026-44248 7.5 - High - May 13, 2026

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the MQTT 5 header Properties section is parsed and buffered before any message size limit is applied. Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the bytesRemainingBeforeVariableHeader > maxBytesInMessage check. The decodeVariableHeader() can call other methods which will call decodeProperties(). Effectively, Netty does not apply any limits to the size of the properties being decoded. Additionally, because MqttDecoder extends ReplayingDecoder, Netty will repeatedly re-parse the enormous Properties sections and buffer the bytes in memory, until the entire thing parses to completion. This can cause high resource usage in both CPU and memory. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Resource Exhaustion

Netty 4.x HttpContentDecompressor OOM DoS via br, zstd, snappy bypass
CVE-2026-42587 7.5 - High - May 13, 2026

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpContentDecompressor accepts a maxAllocation parameter to limit decompression buffer size and prevent decompression bomb attacks. This limit is correctly enforced for gzip and deflate encodings via ZlibDecoder, but is silently ignored when the content encoding is br (Brotli), zstd, or snappy. An attacker can bypass the configured decompression limit by sending a compressed payload with Content-Encoding: br instead of Content-Encoding: gzip, causing unbounded memory allocation and out-of-memory denial of service. The same vulnerability exists in DelegatingDecompressorFrameListener for HTTP/2 connections. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Resource Exhaustion

Netty HttpClientCodec pairing bug fixed in 4.2.13 & 4.1.133
CVE-2026-42584 7.3 - High - May 13, 2026

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that messages body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

HTTP Request Smuggling

Netty DNS Codec Domain Constraint Bypass (<=4.2.13, <=4.1.133)
CVE-2026-42579 7.5 - High - May 13, 2026

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Improper Input Validation

Netty HttpProxyHandler Header Injection (4.2.13.Final/4.1.133.Final)
CVE-2026-42578 7.5 - High - May 13, 2026

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method creates headers using DefaultHttpHeadersFactory.headersFactory().withValidation(false), then adds user-provided outboundHeaders without any CRLF validation. This allows an attacker who can influence the outbound headers to inject arbitrary HTTP headers into the CONNECT request sent to the proxy server. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

HTTP Response Splitting

Netty HTTP request smuggling via chunked/Content-Length before 4.2.13.Final
CVE-2026-42581 7.2 - High - May 13, 2026

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages. The guard is absent for HTTP/1.0. An attacker that sends an HTTP/1.0 request with both headers causes Netty to decode the body as chunked while leaving Content-Length intact in the forwarded HttpMessage. Any downstream proxy or handler that trusts Content-Length over Transfer-Encoding will disagree on message boundaries, enabling request smuggling. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

HTTP Request Smuggling

Spring Boot 4.0.5 Default Security Filter Chain Bypass
CVE-2026-40976 9.1 - Critical - April 27, 2026

In certain circumstances, Spring Boot's default web security is ineffective allowing unauthorized access to all endpoints. For an application to be vulnerable, it must: be a servlet-based web application; have no Spring Security configuration of its own and rely on the default web security filter chain; depend on spring-boot-actuator-autoconfigure; not depend on spring-boot-health. If any of the above does not apply, the application is not vulnerable. Affected: Spring Boot 4.0.04.0.5; upgrade to 4.0.6 or later per vendor advisory.

AuthZ

Spring Boot Weak PRNG in Random Value Property Source (before 4.0.6)
CVE-2026-40975 8.2 - High - April 27, 2026

Values produced by ${random.value} are not suitable for use as secrets. ${random.uuid} is not affected. ${random.int} and ${random.long} should never be used for secrets as they are numeric values with a predictable range. Affected: Spring Boot 4.0.04.0.5 (fix 4.0.6), 3.5.03.5.13 (fix 3.5.14), 3.4.03.4.15 (fix 3.4.16), 3.3.03.3.18 (fix 3.3.19), 2.7.02.7.32 (fix 2.7.33); random value property source / weak PRNG for secrets. Versions that are no longer supported are also affected per vendor advisory.

Use of Insufficiently Random Values

Apache Camel 4.14.x/4.18.x Auth Path Bypass in camel-platform-http-main
CVE-2026-40022 8.2 - High - April 27, 2026

When authentication is enabled on the Apache Camel embedded HTTP server or embedded management server (camel-platform-http-main) and a non-root context path such as /api or /admin is configured via camel.server.path or camel.management.path, the BasicAuthenticationConfigurer and JWTAuthenticationConfigurer classes derive the authentication path from properties.getPath() when camel.server.authenticationPath / camel.management.authenticationPath is not explicitly set. Combined with the Vert.x sub-router mounting model - the sub-router is mounted at _path_* and the authentication handler is registered inside the sub-router at the resolved path - this causes the authentication handler to match only the exact configured context path, not its subpaths. Unauthenticated requests to subpaths such as /api/_route_ or /admin/observe/info therefore reach protected business routes and management endpoints without being challenged for credentials. The /observe/info endpoint can disclose runtime metadata such as the user, working directory, home directory, process ID, JVM and operating system information. This issue affects Apache Camel: from 4.14.1 before 4.14.6, from 4.18.0 before 4.18.2. Users are recommended to upgrade to version 4.20.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, they are suggested to upgrade to 4.14.6. If users are on the 4.18.x LTS releases stream, they are suggested to upgrade to 4.18.2.

Authentication Bypass Using an Alternate Path or Channel

Apache Camel RCE via HeaderFilterStrategy Injection (pre-4.20.0)
CVE-2026-40453 9.9 - Critical - April 27, 2026

The fix for CVE-2025-27636 added setLowerCase(true) to HttpHeaderFilterStrategy so that case-variant header names such as 'CAmelExecCommandExecutable' are filtered out alongside 'CamelExecCommandExecutable'. The same setLowerCase(true) call was not applied to five non-HTTP HeaderFilterStrategy implementations: JmsHeaderFilterStrategy and ClassicJmsHeaderFilterStrategy in camel-jms, SjmsHeaderFilterStrategy in camel-sjms, CoAPHeaderFilterStrategy in camel-coap, and GooglePubsubHeaderFilterStrategy in camel-google-pubsub. Because those strategies use case-sensitive String.startsWith('Camel'/'camel') filtering while the Camel Exchange stores headers in a case-insensitive map, an attacker with JMS (or equivalent) producer access to the broker consumed by a Camel route can inject case-variant Camel internal headers, which are then resolved by downstream components such as camel-exec and camel-file using their canonical casing. This enables remote code execution and arbitrary file write on routes that forward JMS messages to header-driven components. This issue affects Apache Camel: from 3.0.0 before 4.14.6, from 4.15.0 before 4.18.2, from 4.19.0 before 4.20.0. Users are recommended to upgrade to version 4.20.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.6. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.2.

Improper Handling of Case Sensitivity

Apache HttpClient 5.6 Auth Bypass SCRAM-SHA-256 (CVE-2026-40542)
CVE-2026-40542 7.3 - High - April 22, 2026

Missing critical step in authentication in Apache HttpClient 5.6 allows an attacker to cause the client to accept SCRAM-SHA-256 authentication without proper mutual authentication verification. Users are recommended to upgrade to version 5.6.1, which fixes this issue.

Missing Critical Step in Authentication

Spring Security 7.0.07.0.4: Auth ByPass via Servlet Path
CVE-2026-22754 7.5 - High - April 22, 2026

Vulnerability in Spring Spring Security. If an application uses <sec:intercept-url servlet-path="/servlet-path" pattern="/endpoint/**"/> to define the servlet path for computing a path matcher, then the servlet path is not included and the related authorization rules are not exercised. This can lead to an authorization bypass.This issue affects Spring Security: from 7.0.0 through 7.0.4.

Authorization

Spring Security 7.0.0-7.0.4 SubjectX500PrincipalExtractor X.509 CN flaw impersonation
CVE-2026-22747 8.1 - High - April 22, 2026

Vulnerability in Spring Spring Security. SubjectX500PrincipalExtractor does not correctly handle certain malformed X.509 certificate CN values, which can lead to reading the wrong value for the username. In a carefully crafted certificate, this can lead to an attacker impersonating another user. This issue affects Spring Security: from 7.0.0 through 7.0.4.

Improper Validation of Certificate with Host Mismatch

Thymeleaf SSTI Bypass <3.1.4 RELEASE (Expr Exec)
CVE-2026-40478 8.5 - High - April 17, 2026

Thymeleaf is a server-side Java template engine for web and standalone environments. Versions 3.1.3.RELEASE and prior contain a security bypass vulnerability in the the expression execution mechanisms. Although the library provides mechanisms to prevent expression injection, it fails to properly neutralize specific syntax patterns that allow for the execution of unauthorized expressions. If an application developer passes unvalidated user input directly to the template engine, an unauthenticated remote attacker can bypass the library's protections to achieve Server-Side Template Injection (SSTI). This issue has ben fixed in version 3.1.4.RELEASE.

EL Injection

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