Red Hat Build Keycloak

Admin Permission Leak in Keycloak FGAP v2
CVE-2026-14615 4.3 - Medium - July 03, 2026

A flaw was found in the Fine-Grained Admin Permissions (FGAP) v2 implementation within Keycloak's administrative services. When FGAP v2 is enabled, the system fails to properly filter child groups based on the caller's specific permissions when requested through a parent group. This allows a delegated administrator to view details of child groups they are not authorized to access directly, including group names, paths, and custom attributes.

Insufficient Granularity of Access Control

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.

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.

Keycloak Privilege Escalation via Role Mapper Injection
CVE-2026-4629 6.5 - Medium - June 30, 2026

A flaw was found in Keycloak. A highly privileged user with `manage-clients` permission can exploit this vulnerability by injecting a hardcoded role mapper into any client. This action allows the user to bypass existing scope restrictions and inject the `realm-admin` role into generated tokens, resulting in privilege escalation and full administrative access to the realm.

Incorrect Privilege Assignment

Privilege Escalation in Keycloak via Hardcoded Role Mapper
CVE-2026-12388 6.5 - Medium - June 30, 2026

A flaw was found in the Identity Provider (IdP) mapper component of Keycloak, which is used to manage how user information from external services is mapped to Keycloak users. An administrator with limited permissions to manage identity providers can exploit this flaw by creating a "Hardcoded Role" mapper that assigns high-level administrative roles (like realm-admin) to themselves or others. This allows a restricted administrator to bypass security checks and gain full control over the entire realm.

Incorrect Privilege Assignment

Keycloak Admin UI: FGAP bypass via brute-force-user endpoint
CVE-2026-14209 4.3 - Medium - June 30, 2026

A vulnerability was discovered in Keycloak's Admin UI extension that allows certain administrative users to bypass security restrictions. When Fine-Grained Admin Permissions (FGAPv2) are enabled, an administrator who should only be able to search for users (but not view their full details) can use a specific "brute-force-user" endpoint to access a user's full profile. This includes sensitive information and security metadata. The issue occurs because the system fails to check if the administrator has the required "view" permission for that specific user when using this particular search path.

Insecure Direct Object Reference / IDOR

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: Arbitrary File Path Disclosure via Keystore Param
CVE-2026-9083 4.9 - Medium - June 25, 2026

A flaw was found in Keycloak. A realm administrator with the "manage-realm" role can exploit this vulnerability by submitting an arbitrary filesystem path as a keystore parameter when creating a key provider component. This allows the administrator to probe arbitrary filesystem paths, determining which files exist and are readable by the Keycloak process. This information disclosure could be used to identify high-value targets for follow-on attacks.

Directory traversal

Keycloak UMA Prefix Bypass Grants Unauthorized Access Under PERMISSIVE Mode
CVE-2026-9799 4.6 - Medium - June 25, 2026

A flaw was found in org.keycloak.authorization. An authenticated user with a granted User-Managed Access (UMA) permission ticket for one resource can exploit this by using a specific permission request prefix to bypass per-resource access control. This allows the user to gain unauthorized access to all resources of that type within the same resource server, even if they do not have a ticket for those specific resources. This vulnerability requires the resource server to be configured in PERMISSIVE policy enforcement mode and affects typed resources with ownerManagedAccess enabled, where no explicit policy protects the resource type. The primary consequence is unauthorized information disclosure or modification of resources.

Insecure Direct Object Reference / IDOR

Keycloak RAT Allows Reenable Client
CVE-2026-9705 6.5 - Medium - June 25, 2026

A flaw was found in Keycloak's client registration service. A remote attacker, possessing a previously issued Registration Access Token (RAT), could exploit this vulnerability to re-enable a client that an administrator had explicitly disabled. This bypasses security controls, allowing the attacker to reset the client's secret and potentially regain privileged API access. The primary impact includes unauthorized information disclosure and potential integrity compromise.

Insufficient Session Expiration

Keycloak Client Redirect URI Validation Bypass XSS (CVE-2026-9086)
CVE-2026-9086 7.3 - High - June 25, 2026

A flaw was found in Keycloak. A remote attacker with administrative privileges, specifically those with `manage-client` permission or access to client registration endpoints, could bypass client Uniform Resource Identifier (URI) validation. This is achieved by registering a malicious client with a specially crafted redirect URI using a case-insensitive `javascript:` or `data:` scheme. This Cross-Site Scripting (XSS) vulnerability allows for arbitrary code execution in the Keycloak origin when a victim clicks the crafted link, such as in the logout flow or the Admin Console.

XSS

Keycloak Admin API: Missing Auth Checks in GroupResource.addChild
CVE-2026-9099 7.7 - High - June 25, 2026

A flaw was found in Keycloak. A missing authorization check in the GroupResource.addChild() endpoint within the Admin REST API allows an authenticated user with limited administrative privileges to reparent any existing group. When Fine-Grained Admin Permissions v2 (FGAPv2) is enabled, an attacker with management rights over a single low-privilege group can reparent a highly privileged group (such as one possessing the realm-admin role) under their managed group. Because group permissions follow a hierarchical structure, this action unauthorizedly grants the attacker management and password-reset capabilities over the members of the targeted privileged group. An attacker can exploit this to reset an administrator's password, compromise the account, and achieve a full realm takeover, leading to a complete compromise of confidentiality, integrity, and availability.

Insecure Direct Object Reference / IDOR

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

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

Quarkus HTTP Auth Bypass via Encoded ; and / Fixed 3.37.0
CVE-2026-50559 7.5 - High - June 19, 2026

Quarkus is a Java framework for building cloud-native applications. Prior to versions 3.37.0, 3.36.3, 3.33.2.1, 3.33.3, 3.27.4.1, 3.27.5, and 3.20.6.2, Quarkus HTTP path-based authorization policies can be bypassed using encoded semicolons (%3B) to smuggle matrix parameters past the security layer, and using encoded slashes (%2F) or backslashes (%5C) to access protected static resources. This is a distinct issue from CVE-2026-39852, which addressed only literal semicolon stripping. Versions 3.37.0, 3.36.3, 3.33.2.1, 3.33.3, 3.27.4.1, 3.27.5, and 3.20.6.2 contain a patch.

authentification

ws Memory Exhaustion DoS Node.js <5.2.5 6.2.4 7.5.11 8.21.0
CVE-2026-48779 7.5 - High - June 16, 2026

ws is an open source WebSocket client and server for Node.js. All versions from 1.1.0 up to (but not including) 5.2.5, from 6.0.0 up to 6.2.4, from 7.0.0 up to 7.5.11, and from 8.0.0 up to 8.21.0 are affected by a memory exhaustion DoS vulnerability. A peer can send a high volume of exceptionally small fragments and data chunks, with modest network traffic, to force the remote peer into allocating and holding structural wrappers that consume far more memory than the default documented message-size limit, leading to process termination due to OOM. This issue has been fixed in versions 5.2.5, 6.2.4, 7.5.11, and 8.21.0.

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 <=4.2.15 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 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

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

Privilege Escalation in Keycloak admin-ui-ext Bulk Role-Removal
CVE-2026-11986 4.9 - Medium - June 11, 2026

A flaw was found in the admin-ui-ext component of Keycloak, which provides extended administrative user interface capabilities. The issue occurs because certain bulk role-removal endpoints fail to perform granular permission checks when deleting role mappings. This allows a delegated administrator with limited permissions to remove highly privileged roles from other users or groups, potentially disrupting administrative access control.

forced browsing

Micrometer Core & Jetty 1.131.16.5 DoS via crafted HTTP reqs
CVE-2026-40984 7.5 - High - June 09, 2026

In Micrometer, it is possible for a user to provide specially crafted HTTP requests that may cause a denial-of-service (DoS) condition. Affected versions: micrometer-core 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18; 1.9.0 through 1.9.17. micrometer-jetty11 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18. micrometer-jetty12 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18.

Resource Exhaustion

Micrometer 1.15/1.16 gRPC DoS via crafted requests
CVE-2026-40983 7.5 - High - June 09, 2026

In Micrometer, it is possible for a user to provide specially crafted gRPC requests that may cause a denial-of-service (DoS) condition. Affected versions: Micrometer 1.16.0 through 1.16.5; 1.15.0 through 1.15.11.

Resource Exhaustion

Keycloak PartialImport FGAP Escalation via Admin Import
CVE-2026-11577 - June 08, 2026

Keycloak group-member endpoint bypass leads to info disclosure (CVE20269088)
CVE-2026-9088 2.7 - Low - June 05, 2026

A flaw was found in org.keycloak.services. An administrator with delegated access to read group memberships and users can bypass user profile permissions by accessing the group members endpoint. This allows the administrator to view user attributes that are explicitly configured to be denied, leading to information disclosure.

Insufficient Granularity of Access Control

decompress: Zip Slip via Symlink Path Traversal
CVE-2026-10732 7.5 - High - June 05, 2026

All versions of the package decompress are vulnerable to Arbitrary File Write via Archive Extraction (Zip Slip) when extracting a ZIP archive containing two entries with the same path - the first being a symlink to an arbitrary target and the second being a regular file - the file content is written through the symlink to the target location outside the output directory. This is due to the microtask processing order that checks readlink for the second file before resolving symlink for the first file. An attacker can write arbitrary file on the host filesystem potentially leading to remote code execution by providing a specially crafted ZIP archive. **Note:** This bypasses all existing path traversal protections including preventWritingThroughSymlink, added as a part of the fix for [CVE-2020-12265](https://security.snyk.io/vuln/SNYK-JS-DECOMPRESS-557358).

Path Traversal: '\..\filename'

Node.js launch-editor cmd injection via unsanitized file args v<2.9.0
CVE-2024-52011 8.3 - High - June 01, 2026

launch-editor allows users to open files with line numbers in editor from Node.js. Prior to version 2.9.0, due to the insufficient sanitization of the `file` argument in the `launchEditor`, an attacker can execute arbitrary commands on Windows by supplying a filename that contains special characters. This issue has been fixed in the `launch-editor` version 2.9.0, corresponding to vite version 5.4.9.

Command Injection

Keycloak ClientRegistrationAuth DoS via malformed Bearer header
CVE-2026-9803 5.3 - Medium - May 28, 2026

A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.

Out-of-bounds Read

Keycloak token replay after revocation via server restart
CVE-2026-9802 6.8 - Medium - May 28, 2026

A flaw was found in Keycloak. When revokeRefreshToken=true is enabled and persistent session storage is in use, a server restart can reset internal timing mechanisms. This allows a remote attacker, who has previously captured a user's refresh token, to replay that token even after it has been revoked. Successful exploitation grants the attacker unauthorized access to the victim's account, potentially leading to information disclosure or privilege escalation.

Insufficient Session Expiration

Keycloak LDAP Password Policy DoS via OutOfMemoryError
CVE-2026-9801 4.9 - Medium - May 28, 2026

A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or an attacker compromising an upstream LDAP server, could exploit this vulnerability. By sending a malformed LDAP password policy response during a password authentication request, the attacker can trigger an OutOfMemoryError. This causes the Keycloak Java Virtual Machine (JVM) to terminate, leading to a denial of service (DoS) for all realms on the affected node.

Improper Validation of Specified Quantity in Input

Keycloak CIBA flow bypass for account lock via brute-force
CVE-2026-9798 4.3 - Medium - May 28, 2026

A flaw was found in Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts.

Authentication Bypass by Primary Weakness

Keycloak TOCTOU Privilege Escalation via Role Check Exploit
CVE-2026-9796 6.5 - Medium - May 28, 2026

A flaw was found in Keycloak. An authenticated administrator with the `manage-clients` role can exploit a Time-of-check to time-of-use (TOCTOU) vulnerability in the name-based admin role checks. This allows the attacker to escalate their privileges to `realm-admin` for all users within the realm, granting them extensive control over the system. The composite role relationship persists even after the attacker's own permissions are revoked and across system reboots.

TOCTTOU

Keycloak FGAPv2 Role Assignment Bypass Exploits Admin Permissions
CVE-2026-9795 7.3 - High - May 28, 2026

A flaw was found in Keycloak's Fine-Grained Admin Permissions (FGAPv2) feature. An administrator with limited client management permissions can exploit this vulnerability to assign any realm role, including highly privileged roles, to a client's scope mapping. This bypasses intended security controls, allowing the injected role to be projected into a user's authentication token when they access the modified client. This could lead to unauthorized privilege escalation within the Keycloak realm.

Incorrect Privilege Assignment

Keycloak SAML ECP Info Disclosure via SOAP XML Fault Strings
CVE-2026-9794 5.3 - Medium - May 28, 2026

A flaw was found in Keycloak. A remote, unauthenticated attacker can exploit this vulnerability by sending specially crafted SOAP requests to the SAML ECP (Security Assertion Markup Language Enhanced Client or Proxy) endpoint with varying client IDs. By observing distinct faultstrings in the responses, the attacker can determine the client's protocol type, leading to information disclosure.

Generation of Error Message Containing Sensitive Information

Keycloak Client Policy Bypass Enables Unauth ROPC Grant
CVE-2026-9792 6.5 - Medium - May 28, 2026

A flaw was found in Keycloak's Client Policies, specifically within the `org.keycloak.protocol.oidc` component. When certain condition providers (client-type, client-roles, client-attributes, client-scopes) are used to enforce security restrictions, the `reject-ropc-grant` executor is silently bypassed. This allows an unauthenticated remote attacker to obtain tokens via a Resource Owner Password Credentials (ROPC) grant, even when a policy is explicitly configured to block it. This bypass can lead to unauthorized access and information disclosure.

Improper Handling of Insufficient Permissions or Privileges

Keycloak JWE Decryption Bypass Allows Unauthorized OIDC Claims via Signature Oversight
CVE-2026-9793 5.9 - Medium - May 28, 2026

A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.

Improper Verification of Cryptographic Signature

Keycloak OIDC Org Metadata Leak via Authz Bypass
CVE-2026-9791 4.3 - Medium - May 28, 2026

A flaw was found in Keycloak. An authenticated user with existing organization membership can exploit this flaw by accessing user-facing APIs, such as the account API or by requesting an OpenID Connect (OIDC) token with the 'organization' scope. This allows organization metadata to be disclosed in tokens, even after an administrator has explicitly disabled the Organizations feature, potentially leading to incorrect authorization decisions by resource servers.

AuthZ

Keycloak TokenEndpoint JWT Length Bypass Escalates Privileges
CVE-2026-9704 6.8 - Medium - May 27, 2026

A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subject_token JSON Web Token (JWT) to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client credentials. This allows the user to gain the permissions of the client's service account, leading to privilege escalation.

Improper Validation of Specified Quantity in Input

Keycloak HTTP Parameter Pollution via Broad Redirect URIs
CVE-2026-9689 4.2 - Medium - May 27, 2026

A flaw was found in Keycloak, an open-source identity and access management solution. When a client application is configured to accept broad redirect Uniform Resource Identifiers (URIs), a remote attacker can manipulate the authentication process by crafting a special web address. If a user clicks this link, the client application might incorrectly prioritize attacker-controlled information over legitimate data. This vulnerability, known as HTTP parameter pollution, could allow an attacker to bypass security measures or gain unauthorized access to resources.

Improper Validation of Consistency within Input

Keycloak Cross-Session Verification Key Allows Upstream IdP Account Consuming
CVE-2026-9087 6.4 - Medium - May 20, 2026

A flaw was found in Keycloak. The cross-session verification proof is keyed only by (local userId, idpAlias) and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account.

Insecure Direct Object Reference / IDOR

Keycloak OIDC implicit flow bypass & token leakage
CVE-2026-7571 7.1 - High - May 19, 2026

A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.

Assumed-Immutable Parameter Tampering

Session Fixation in Keycloak /login-actions restart endpoint (SSO takeover)
CVE-2026-7507 7.5 - High - May 19, 2026

A session fixation vulnerability was found in Keycloak's login-actions endpoints. An unauthenticated attacker could exploit this flaw by pre-creating an authentication session and tricking a victim into visiting a maliciously crafted link. By leveraging the /login-actions/restart endpointwhich processes session handles without adequate CSRF protection or cookie ownership validationan attacker can reset the authentication flow state. This causes Single Sign-On (SSO) to authenticate the victim transparently upon clicking the link, allowing the attacker to hijack the required-action form without needing the victim's credentials. A successful exploit could lead to complete account takeover, including highly privileged administrative accounts.

Authentication Bypass by Spoofing

Keycloak Wildcard Redirect URI Validation Bypass (CVE-2026-7504)
CVE-2026-7504 8.1 - High - May 19, 2026

A flaw was found in Keycloak's URL validation logic during redirect operations. By crafting a malicious request, an attacker could bypass validation to redirect users to unauthorized URLs, potentially leading to the exposure of sensitive information within the domain or facilitating further attacks. This vulnerability specifically affects Keycloak clients configured with a wildcard (*) in the "Valid Redirect URIs" field and requires user interaction to be successfully exploited. The issue stems from a discrepancy in how Keycloak and the underlying Java URI implementation handle the user-info component of a URL. If a malicious redirect URL is constructed using multiple @ characters in the user-info section, Java's URI parser fails to extract the user-info, leaving only the raw authority field. Consequently, Keycloak's validation check fails to detect the malformed user-info, falls back to a wildcard comparison, and incorrectly permits the malicious redirect.

Open Redirect

Keycloak WebAuthn Replay of ExecuteActionsActionToken
CVE-2026-37982 6.8 - Medium - May 19, 2026

A flaw was found in Keycloak. This authentication vulnerability allows a remote attacker to replay `ExecuteActionsActionToken` tokens within Keycloak's WebAuthn (Web Authentication) flow. By intercepting an execute-actions email link, an attacker can register their own authenticator to a victim's account. This leads to unauthorized enrollment of a hardware-backed credential, enabling persistent account takeover.

Authentication Bypass by Capture-replay

Keycloak Admin API PII Leak via view-clients evaluate-scopes
CVE-2026-37978 4.9 - Medium - May 19, 2026

A flaw was found in Keycloak. A low-privilege administrator with the 'view-clients' role can exploit this by invoking the 'evaluate-scopes' Admin API endpoints with an arbitrary user ID (userId) parameter. This vulnerability allows for cross-role personally identifiable information (PII) leakage, enabling unauthorized visibility into user identities and authorizations across the realm. Exploitation is possible remotely via network access to the Admin API.

Insecure Direct Object Reference / IDOR

Keycloak OIDC Introspection Audience Bypass Vulnerability
CVE-2026-37979 6.5 - Medium - May 19, 2026

A flaw was found in Keycloak. This access control vulnerability in Keycloak's OpenID Connect (OIDC) token introspection endpoint allows a confidential client to bypass audience restrictions. An attacker-controlled client with valid credentials can retrieve sensitive token claims intended for other resource servers, compromising the confidentiality of lightweight access tokens. This issue can be exploited remotely by any confidential client in the realm with valid credentials.

Authorization