Red Hat Openstack
Don't miss out!
Thousands of developers use stack.watch to stay informed.Get an email whenever new security vulnerabilities are reported in Red Hat Openstack.
Recent Red Hat Openstack Security Advisories
| Advisory | Title | Published |
|---|---|---|
| RHSA-2026:80684 | (RHSA-2026:80684) Updated Red Hat OpenStack Platform 17.1 director Operator container images | October 12, 2026 |
| RHSA-2026:66401 | (RHSA-2026:66401) Important: Red Hat OpenStack Platform 17.1 security and bug fix advisory | September 10, 2026 |
| RHSA-2026:39812 | (RHSA-2026:39812) Important: Red Hat OpenStack Services on OpenShift 18.0 (openstack-glance) security update | July 15, 2026 |
| RHSA-2026:39811 | (RHSA-2026:39811) Important: Red Hat OpenStack Services on OpenShift 18.0 (openstack-ironic) security update | July 15, 2026 |
| RHSA-2026:39810 | (RHSA-2026:39810) Important: Red Hat OpenStack Services on OpenShift 18.0 (golang-github-openstack-k8s-operators-os-diff) security update | July 15, 2026 |
| RHSA-2026:39809 | (RHSA-2026:39809) Important: Red Hat OpenStack Services on OpenShift 18.0 (erlang) security update | July 15, 2026 |
| RHSA-2026:39808 | (RHSA-2026:39808) Important: Red Hat OpenStack Services on OpenShift 18.0 (openstack-keystone) security update | July 15, 2026 |
| RHSA-2026:28047 | (RHSA-2026:28047) Important: Red Hat OpenStack Platform 17.1 (etcd) security update | June 22, 2026 |
| RHSA-2026:28046 | (RHSA-2026:28046) Moderate: Red Hat OpenStack Platform 17.1 (golang-uber-multierr) security update | June 22, 2026 |
| RHSA-2026:28044 | (RHSA-2026:28044) Important: Red Hat OpenStack Platform 17.1 (openstack-keystone) security update | June 22, 2026 |
By the Year
In 2026 there have been 90 vulnerabilities in Red Hat Openstack with an average score of 7.6 out of ten. Last year, in 2025 Openstack had 3 security vulnerabilities published. That is, 87 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 2.34.
| Year | Vulnerabilities | Average Score |
|---|---|---|
| 2026 | 90 | 7.58 |
| 2025 | 3 | 5.23 |
| 2024 | 15 | 6.32 |
| 2023 | 7 | 5.11 |
| 2022 | 8 | 6.80 |
| 2021 | 2 | 7.50 |
| 2020 | 24 | 5.64 |
| 2019 | 30 | 7.29 |
| 2018 | 56 | 6.64 |
It may take a day or so for new Openstack 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 Openstack Security Vulnerabilities
Ansible Operator Plugins: Jinja2 Template Injection Enables ClusterWide PrivEsc
CVE-2026-92982
8.5 - High
- October 15, 2026
A flaw was found in Ansible Operator Plugins. A low-privileged Kubernetes user can exploit a Jinja2 template injection vulnerability by crafting malicious custom resource (CR) specification values. These values are processed by Ansible without proper sanitization, allowing embedded Jinja2 expressions to be executed within the operator pod. This can lead to arbitrary code execution and privilege escalation, granting the attacker control over the operator's service account with cluster-wide permissions.
1336
DPDK vhost-crypto Integer Overflow, Host Buffer Overrun
CVE-2026-86849
6.5 - Medium
- October 14, 2026
A flaw was found in DPDK lib/vhost vhost-crypto. Integer overflow in chain length checks, and missing length checks on the RSA path, can overflow a host buffer in the vhost-crypto backend.
Memory Corruption
DPDK nfp vDPA Driver Buffer Overflow via Excess Virtqueues
CVE-2026-86856
6.5 - Medium
- October 14, 2026
A flaw was found in the DPDK nfp vDPA driver. Stack and heap buffers sized for a single queue pair can be overflowed when more virtqueues are configured, leading to a host crash or memory corruption.
Memory Corruption
DPDK vhost-crypto Uninitialized Next Pointer Crash in Write-Back Chain
CVE-2026-86847
6.5 - Medium
- October 14, 2026
A flaw was found in DPDK lib/vhost vhost-crypto. Write-back chain cleanup can follow an uninitialized next pointer when mapping a guest descriptor fails, causing the host vhost-crypto process to hang or crash.
Access of Uninitialized Pointer
DPDK vhost-crypto OOB Write via Unchecked Avail-Ring Index
CVE-2026-86846
6.5 - Medium
- October 14, 2026
A flaw was found in DPDK lib/vhost vhost-crypto. A guest can supply an avail-ring descriptor index that is used without bounds checking, causing an out-of-bounds write in the host vhost-crypto backend.
Memory Corruption
DPDK vhost-crypto Use-after-Free via stale session pointer
CVE-2026-86845
6.5 - Medium
- October 14, 2026
A flaw was found in DPDK lib/vhost vhost-crypto. Session cleanup can leave a stale cached session pointer, and the data path does not check the session type before attaching it, leading to use-after-free or type confusion in the host vhost-crypto backend.
Dangling pointer
DPDK lib/vhost RX Descriptor Underflow Causes VDS in OVSDPDK
CVE-2026-86566
6.5 - Medium
- October 14, 2026
A flaw was found in DPDK lib/vhost. A guest with runt RX descriptors can underflow the copy length in vhost enqueue, causing a denial of service in a shared vhost backend such as OVS-DPDK.
Integer underflow
DPDK lib/vhost vhost-crypto Indirect-Descriptor OOB via double-fetch
CVE-2026-86848
8.8 - High
- October 14, 2026
A flaw was found in DPDK lib/vhost vhost-crypto. The indirect-descriptor snapshot double-fetches a guest descriptor next index, allowing a malicious guest to cause an out-of-bounds access in the host backend.
TOCTTOU
DPDK lib/vhost UAF via IOTLB miss leading to use-after-unmap
CVE-2026-86567
8.8 - High
- October 14, 2026
A flaw was found in DPDK lib/vhost. The VDUSE handler fails to invalidate vring pointers when the IOTLB is invalidated, leading to use-after-unmap.
Dangling pointer
DPDK lib/vhost OOB write via virtqueue size desync
CVE-2026-86565
8.2 - High
- October 14, 2026
A flaw was found in DPDK lib/vhost. A guest can desynchronize virtqueue size from inflight descriptor table size, causing an out-of-bounds write in the host vhost process.
Memory Corruption
DPDK vhost double-offset bug causes memory access error
CVE-2026-86563
7.8 - High
- October 14, 2026
A flaw was found in DPDK lib/vhost. A double-offset bug in vhost log mapping calculation can lead to incorrect memory access.
Incorrect Calculation of Buffer Size
DPDK VHOST TOCTOU Double-Fetch Heap Overflow Vulnerability
CVE-2026-86562
7.8 - High
- October 14, 2026
A flaw was found in DPDK lib/vhost. A TOCTOU double-fetch of control-queue descriptors allows a heap buffer overflow with attacker-controlled content in the VDUSE control-queue handler.
Race Condition
DPDK vhost mmap size validation flaw leads to host crash
CVE-2026-86561
6.5 - Medium
- October 14, 2026
A flaw was found in DPDK lib/vhost. Memory size is not adequately validated before mmap during vhost memory-region setup, which can lead to a host crash or memory corruption.
Allocation of Resources Without Limits or Throttling
DPDK vhost OOB heap copy via indirect descriptor table
CVE-2026-93683
6.4 - Medium
- October 14, 2026
A flaw was found in the DPDK vhost library. When handling a virtio indirect descriptor table, the host reads the table length more than once from guest memory and can allocate a host copy before validating that length. A guest that changes the length between those reads, or that supplies an out-of-range next index on a small host copy in the vDPA relay path, can cause the host vhost process to walk past the validated mapping or heap copy. That can crash or disrupt the vhost process. Out-of-bounds bytes are consumed as descriptor fields for GPA translation and are not returned to the guest as payload. This is a residual issue in the non-contiguous indirect descriptor copy path introduced as part of the CVE-2018-1059 fix.
TOCTTOU
OpenStack Network Exporter Basic Auth Bypass via TLS Misconfig
CVE-2026-83535
7.4 - High
- October 12, 2026
A flaw was found in openstack-network-exporter. When an operator configures user authentication but omits or misconfigures Transport Layer Security (TLS), the basic authentication mechanism is silently bypassed. This fail-open design allows an adjacent network attacker to access sensitive Open vSwitch (OVS) and Open Virtual Network (OVN) dataplane metrics without credentials. Consequently, an attacker can enumerate bridge names, port counters, OVN controller state, and host topology, leading to information disclosure.
Observable Timing Discrepancy
openstack-network-exporter DoS via missing ReadHeaderTimeout
CVE-2026-83536
5.3 - Medium
- October 12, 2026
A flaw was found in openstack-network-exporter. The HTTP server within the component is configured without essential timeout settings, such as ReadHeaderTimeout. This vulnerability allows an unauthenticated, remote attacker to initiate multiple slow HTTP header connections. By trickling header bytes, the attacker can exhaust server resources, specifically file descriptors, leading to a Denial of Service (DoS) that prevents legitimate Prometheus metric scraping and alerting.
Resource Exhaustion
Ansible Core Tarball Path Traversal via Symlink Chain Exploit
CVE-2026-89091
8.8 - High
- October 08, 2026
A flaw was found in ansible-core. When installing a collection with `ansible-galaxy collection install`, the archive extractor validates member paths using lexical path normalisation (os.path.abspath) instead of resolving symbolic links (os.path.realpath), and it performs no containment check on symlink-typed directory members before creating them. A crafted collection tarball can chain symlink directory entries so that a subsequent file member is written outside the intended destination directory. This allows an attacker who can get a victim to install a malicious collection to overwrite arbitrary files with the privileges of the user running ansible-galaxy, leading to code execution on the control node. This is a bypass of the fix for CVE-2020-10691.
insecure temporary file
Use-after-Free in QEMU 9pfs Enables VM Escape
CVE-2026-93834
8.8 - High
- September 25, 2026
A use-after-free vulnerability was found in QEMU's 9pfs subsystem. A race condition between the main thread and a worker thread when processing concurrent Tlcreate and Twalk requests allows a malicious guest user to craft a fid path containing stale heap data, bypassing directory traversal restrictions and escaping the shared directory boundary. This can lead to arbitrary host file read/write and code execution (VM escape) as the QEMU process user.
Dangling pointer
Privilege Escalation via VAPIC Alias Overflow in QEMU
CVE-2026-81627
8.2 - High
- September 18, 2026
A flaw was found in QEMU. The VAPIC setup hypercall in hw/i386/vapic.c does not validate that the writable RAM alias remains within the option ROM window. A privileged guest user on a Q35/KVM machine can position this alias over locked SMRAM, bypassing chipset D_LCK protection and injecting code into System Management Mode memory.
Memory Corruption
Redis Community Cluster Bus OOB Read via Unchecked Null-Termination
CVE-2026-92925
7.1 - High
- September 17, 2026
A flaw was found in Redis community. The cluster bus packet parser, responsible for handling PING, PONG, and MEET packets, fails to properly validate string-carrying extensions for null-termination. This oversight allows a remote attacker to craft a malicious packet, leading to an out-of-bounds read when the packet's payload is processed. Successful exploitation of this vulnerability could result in the disclosure of sensitive information or a remote denial of service (DoS).
Out-of-bounds Read
jwcrypto JWK.import_key() DoS via unbounded key_ops array
CVE-2026-92091
5.9 - Medium
- September 16, 2026
A flaw was found in jwcrypto. The JWK.import_key() function validates the key_ops JWK member for duplicate values using an algorithm with O(n^2) time complexity, and the length of key_ops is not bounded. A remote, unauthenticated attacker can supply a JWK with a large key_ops array to an application that passes attacker-controlled key material to a public key-import API (reachable via ECDH-ES key agreement, OIDC dynamic client registration, DPoP, or ACME account key registration, among others) to consume excessive CPU time, resulting in a denial of service.
Inefficient Algorithmic Complexity
Leapp Upgrade root privilege escalation via MySQL plugin
CVE-2026-75092
7.3 - High
- September 15, 2026
A privilege escalation flaw was found in the scan_mysql actor of leapp-upgrade-el9toel10 (provided by leapp-repository). During RHEL 9 to RHEL 10 upgrades, the actor runs: mysqld --validate-config --log-error-verbosity=2 directly as root in the Leapp actor context, bypassing the packaged MySQL systemd unit that normally starts the daemon as User=mysql. A process compromised as the mysql OS identity can write a version-2 persisted configuration (mysqld-auto.cnf) and a malicious shared object into /var/lib/mysql (a directory owned by mysql). That persisted map can set plugin_dir to /var/lib/mysql and early_plugin_load (or related loader options such as plugin_load / plugin_load_add) so MySQL loads the attacker-controlled object during configuration validation. Plugin loading can reach dlopen() before MySQLs runtime-user check and before plugin-symbol validation. When an administrator subsequently runs the documented Leapp preupgrade or upgrade workflow, attacker-controlled code can execute as UID 0 with a full capability set in an unconfined SELinux domain (unconfined_t). The attack does not require write access to the default system plugin path under /usr; redirecting plugin_dir via mysql-owned persisted state is sufficient. Ordinary SQL privileges alone (including highly privileged SQL accounts) are not a sufficient startpoint OS-level execution as the mysql service identity is required, plus later administrator invocation of Leapp.
Execution with Unnecessary Privileges
PCS: Local File Disclosure via pcs host auth --token
CVE-2026-84828
6.5 - Medium
- September 10, 2026
A flaw was found in PCS (Pacemaker Configuration System). A local attacker with membership in the 'haclient' group can exploit the 'pcs host auth --token' command to read the contents of arbitrary files on the filesystem, provided the files are shorter than 256 bytes. The file contents are read with root privileges by the pcsd daemon and can be exfiltrated by the attacker through subsequent cluster node communication. This allows disclosure of sensitive data such as API keys, tokens, or configuration secrets that would otherwise be inaccessible to the attacker.
Incorrect Permission Assignment for Critical Resource
Ansible community.general OCAPI Modules Disable TLS Validation (CVE-2026-87872)
CVE-2026-87872
6.8 - Medium
- September 09, 2026
A flaw was found in the OCAPI modules (ocapi_command, ocapi_info) of the community.general Ansible collection. The shared OCAPI request helper disables TLS certificate validation on every request and the modules expose no parameter to re-enable it, while sending HTTP Basic-Auth credentials to an https endpoint. An attacker positioned on the network path between the Ansible controller and the OCAPI-managed storage/enclosure device can present any certificate, intercept the session, capture the credentials, and tamper with responses.
Improper Certificate Validation
Ansible community.general memcached cache plugin RCE via pickle deserialization
CVE-2026-87874
8.1 - High
- September 09, 2026
A flaw was found in the memcached cache plugin of the community.general Ansible collection. Although its documentation states that records are stored in JSON format, the plugin performs no explicit serialization and relies on python-memcached, which pickles values on write and unpickles them on read. Because memcached is unauthenticated and cache keys are predictable, an attacker able to reach a network-exposed or shared memcached instance can write a crafted pickle payload that is deserialized and executed on the Ansible controller when the poisoned fact cache is next read, leading to remote code execution.
Marshaling, Unmarshaling
jwcrypto General JWS Verification Bypass via Key ID Misidentification
CVE-2026-84185
5.9 - Medium
- September 03, 2026
A flaw was found in the jwcrypto library, which is used for implementing Javascript Object Signing and Encryption (JOSE) standards. The issue occurs when the library verifies a General JSON Serialization JWS using a set of keys. Due to a coding error, the library fails to correctly identify the specific key ID (kid) and may instead accept a signature made by any valid key in the set. This can allow an attacker with a valid key to bypass authorization checks in applications that rely on the key ID to identify specific tenants or users.
Improper Verification of Cryptographic Signature
jwcrypto JWE Deserialization Memory Overrun DoS
CVE-2026-80179
5.9 - Medium
- August 27, 2026
A flaw was found in jwcrypto. A remote attacker can send a specially crafted JSON Web Encryption (JWE) token containing numerous period delimiters. This malformed token can force the JWE.deserialize() function to allocate excessive memory, leading to a MemoryError. This issue results in a denial of service (DoS) for services that process untrusted JWE values.
Allocation of Resources Without Limits or Throttling
Unlogged Kerberos Bind Password Leak via Ansible ipa_getkeytab
CVE-2026-80158
5.5 - Medium
- August 26, 2026
A flaw was found in the ipa_getkeytab module of the community.general Ansible collection. The module's bind_pw parameter, used to supply the LDAP simple-bind password when retrieving a Kerberos keytab, is not declared with no_log, unlike the sibling password parameter in the same module. As a consequence, the supplied IPA/LDAP bind password is recorded in cleartext in the managed host's system journal/syslog (the module's "Invoked with" record), is included in the module's return values and verbose (-v) output, and is displayed in Automation Controller / AWX job output. The password is additionally passed on the command line to the ipa-getkeytab helper (as --bindpw <value>), exposing it in the process list to local users while the command runs. An attacker able to read these logs, job output, or the process table can obtain the directory bind credential, potentially compromising the accounts and objects that credential can access.
Invocation of Process Using Visible Sensitive Information
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
Erlang OTP erts(inet_drv) stack overflow via SCTP ERROR prior 27.3.4.13
CVE-2026-49759
8.2 - High
- June 10, 2026
Stack-based Buffer Overflow vulnerability in Erlang OTP erts (inet_drv) allows an unauthenticated remote attacker to crash the BEAM VM by sending a crafted SCTP ERROR chunk. The sctp_parse_error_chunk function in erts/emulator/drivers/common/inet_drv.c parses SCTP ERROR chunks and writes cause codes into a fixed-size stack-allocated ErlDrvTermData spec[] array without checking bounds. A remote attacker who has established an SCTP association to a listening port can send a single crafted SCTP ERROR chunk containing enough cause codes to overflow the stack buffer, crashing the VM. The attacker can only write 16-bit values interleaved with a fixed tag, so the overflow does not provide a controlled return address, limiting exploitation to Denial of Service. A crafted SCTP ERROR chunk may also leak bits and pieces of Erlang VM memory into the received error packet observed by the Erlang process. Such data is already readable by the user running the Erlang VM, so the disclosure scope is limited. This issue affects OTP from OTP 17.0 before OTP 27.3.4.13, OTP 28.5.0.2, and OTP 29.0.2, corresponding to erts from 6.0 before 15.2.7.9, 16.4.0.2, and 17.0.2. Whether OTP before OTP 17.0, corresponding to erts before 6.0, is affected is unknown.
Stack Overflow
ansible authorized_key LPE via untrusted symlink
CVE-2026-11837
7.3 - High
- June 10, 2026
A local privilege escalation vulnerability was found in the ansible.posix authorized_key module. The module's keyfile() function uses os.chown() instead of os.lchown() and opens files without O_NOFOLLOW when managing SSH authorized keys. An unprivileged local user can pre-stage symbolic links in their ~/.ssh directory to redirect file ownership changes to arbitrary system paths when an operator runs the authorized_key task as root, leading to local privilege escalation.
insecure temporary file
Unauth Service Crash via Crafted JSON in OpenStack Ironic 32-35.0.1
CVE-2026-50589
7.5 - High
- June 04, 2026
In OpenStack Ironic 32 before 37.0.0, an unauthenticated malicious user could submit a crafted JSON string to some endpoints on the API or JSON-RPC service and effect a service crash.
Allocation of Resources Without Limits or Throttling
OpenStack Mistral RCE via API before 22.0.0
CVE-2026-41283
9.9 - Critical
- June 04, 2026
OpenStack Mistral through 22.0.0 allows Arbitrary Remote Code Execution when the API is exposed. There are endpoints that allow code execution, which can lead to exfiltration of service credentials.
AuthZ
OpenStack oslo.messaging TLS Hostname Verification Bypass (1.0.0-17.3.0)
CVE-2026-44393
7.4 - High
- June 04, 2026
An issue was discovered in OpenStack oslo.messaging 1.0.0 through 17.3.0. The oslo.messaging RabbitMQ driver does not perform TLS hostname verification when connecting to the message broker. When ssl_ca_file is configured, the driver enables certificate chain validation but does not pass the expected broker hostname into the underlying TLS stack. Any certificate signed by the deployment CA is accepted regardless of hostname, allowing an attacker who can intercept control-plane traffic to impersonate the RabbitMQ broker and perform a man-in-the-middle attack on RPC and notification traffic. All OpenStack services using oslo.messaging with RabbitMQ over TLS are affected.
Improper Validation of Certificate with Host Mismatch
Go crypto/x509 VerifyHostname DNS SAN quadratic overhead
CVE-2026-27145
7.5 - High
- June 02, 2026
(*x509.Certificate).VerifyHostname previously called matchHostnames in a loop over all DNS Subject Alternative Name (SAN) entries. This caused strings.Split(host, ".") to execute repeatedly on the same input hostname. With a large DNS SAN list, verification costs scaled quadratically based on the number of SAN entries multiplied by the hostname's label count. Because x509.Verify validates hostnames before building the certificate chain, this overhead occurred even for untrusted certificates.
Unchecked Input for Loop Condition
OpenStack Keystone RBAC Bypass via Untrusted JSON Merge (pre-29.0.2)
CVE-2026-42999
8.3 - High
- May 28, 2026
An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone RBAC policy enforcer in enforce_call unconditionally merges the raw JSON request body into the policy enforcement dictionary via policy_dict.update(json_input.copy()), overwriting trusted target data that was previously set from database lookups. Because flask.request.get_json is called with force=True, this works regardless of Content-Type or HTTP method. Any authenticated user can inject arbitrary policy target attributes (e.g., user_id, project_id) into the request body to bypass RBAC checks and perform unauthorized operations on resources belonging to other users or projects. This was introduced in commit 5ea59f52 (Rocky/14.0.0).
AuthZ
OpenStack Keystone Pre-29.0.2 Priv Esc via Impersonation + Trust
CVE-2026-43000
8.4 - High
- May 28, 2026
An issue was discovered in OpenStack Keystone before 29.0.2. When combined with an application credential impersonation vulnerability, an attacker with the member role on a project can escalate to admin by chaining unrestricted application credentials with Keystone trusts. The impersonated token carries the victim's identity, which passes the trustor validation check. Keystone then validates the delegated roles against the victim's actual role assignments in the database, not the roles on the requesting token. This allows the attacker to create a trust delegating the victim's admin role to themselves. The trust persists independently, and additional trusts and application credentials can be created to maintain access. All actions are logged under the victim's identity.
AuthZ
OTP public_key nameConstraints bypass via CN fallback (26.2.5.21)
CVE-2026-42790
7.4 - High
- May 27, 2026
Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_cert and public_key modules) allows a DNS nameConstraints bypass via subject CommonName fallback in TLS hostname verification. Two flaws combine to allow a subordinate CA whose DNS nameConstraints are restricted (e.g. permitted;DNS:allowed.example.com) to issue a leaf certificate that an OTP TLS client accepts as a valid identity for an out-of-scope hostname (e.g. victim.example.com): First, pubkey_cert:validate_names/6 in lib/public_key/src/pubkey_cert.erl only checks SAN DNS entries against nameConstraints. Per RFC 5280, a permitted DNS subtree only restricts certificates that contain a DNS-typed name. A leaf with no subjectAltName therefore trivially satisfies any permitted;DNS:... constraint regardless of its subject commonName. Second, public_key:pkix_verify_hostname/3 in lib/public_key/src/public_key.erl falls back to the subject commonName when no subjectAltName is present, extracting id-at-commonName attributes as presented IDs and matching them against the reference hostname. The strict pkix_verify_hostname_match_fun(https) matcher does not suppress this fallback. The result is that path validation accepts a CN-only leaf under a DNS-constrained intermediate (no SAN means the nameConstraints are not triggered), and hostname verification then accepts it via the CN fallback. The bypass is reachable from stock ssl:connect with verify_peer, a trusted CA, SNI, and the canonical strict https hostname matcher. This issue affects OTP from OTP 19.3 before OTP 29.0.1, OTP 28.5.0.1, OTP 27.3.4.12 and OTP 26.2.5.21, corresponding to public_key from 1.4 before 1.21.1, 1.20.3.1, 1.17.1.3 and 1.15.1.7.
Improper Certificate Validation
Erlang/OTP public_key (pre-1.15.1) Bypass Chain-of-Trust via Non-CA
CVE-2026-42789
8 - High
- May 27, 2026
Improper Following of a Certificate's Chain of Trust vulnerability in Erlang OTP public_key (pubkey_cert module) allows a non-CA certificate to be accepted as an intermediate issuer, enabling certificate chain forgery. In lib/public_key/src/pubkey_cert.erl, pubkey_cert:validate_extensions/7 contains two flaws that together allow a certificate with basicConstraints cA:false and no keyUsage extension to be used as an intermediate issuer in a chain passed to public_key:pkix_path_validation/3: the cA:false clause recurses into the remaining extensions without rejecting the certificate when it is in issuer position, and the keyUsage check only fires when the extension is present, so a certificate lacking keyUsage entirely bypasses the keyCertSign enforcement. Any party holding an end-entity certificate with basicConstraints cA:false and no keyUsage extension, issued by any CA in the victim's trust store, can use that certificate's private key to sign forged leaf certificates for arbitrary identities. public_key:pkix_path_validation/3 accepts the resulting chain, and by extension every TLS or mTLS endpoint built on the OTP ssl application that relies on the default verifier is affected, including server identity verification on the client side and client certificate verification on mTLS servers. This issue affects OTP from OTP 17.0 before OTP 27.3.4.19, OTP 28.5.0.8, and OTP 29.1.2, corresponding to public_key from 0.22 before 1.17.1.7, 1.20.3.6, and 1.21.8. Whether OTP before OTP 17.0, corresponding to public_key before 0.22, is affected is unknown.
Improper Certificate Validation
golang.org/x/net/idna pre-0.55.0 IDN bug allows silent ASCII/Unicode mix
CVE-2026-39821
8.2 - High
- May 22, 2026
The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode("xn--example-.com") incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna package. For example, a program which performs privilege checks on the ASCII hostname may reject "example.com" but permit "xn--example-.com". If that program subsequently converts the ASCII hostname to Unicode, it will inadvertently permits access to the Unicode name "example.com".
Improper Validation of Unsafe Equivalence in Input
KnownHosts Revocation Check Failure in golang.org/x/crypto/ssh<0.52.0
CVE-2026-42508
7.4 - High
- May 22, 2026
Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked.
Improper Certificate Validation
Auth Bypass in golang.org/x/crypto/ssh <0.52.0
CVE-2026-46595
7.1 - High
- May 22, 2026
Previously, CVE-2024-45337 fixed an authorization bypass for misused ssh server configurations; if any other type of callback is passed other than public key, then the source-address validation would be skipped.
AuthZ
golang.org/x/crypto/ssh: CertChecker nil callback panic <0.52.0
CVE-2026-39835
7.5 - High
- May 22, 2026
SSH servers which use CertChecker as a public key callback without setting IsUserAuthority or IsHostAuthority could be caused to panic by a client presenting a certificate. CertChecker now returns an error instead of panicking when these callbacks are nil.
NULL Pointer Dereference
Resource Leak in golang.org/x/crypto/ssh <0.52.0 via Global Request Buffers
CVE-2026-39830
7.5 - High
- May 22, 2026
A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.
Missing Release of Resource after Effective Lifetime
go/crypto/ssh CPU DoS via oversized RSA/DSA keys before 0.52
CVE-2026-39829
7.5 - High
- May 22, 2026
The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.
Improper Validation of Specified Quantity in Input
SSH Auth PartialSuccessError Permissions Discarded (golang.org/x/crypto/ssh <0.52.0)
CVE-2026-39828
8.8 - High
- May 22, 2026
When an SSH server authentication callback returned PartialSuccessError with non-nil Permissions, those permissions were silently discarded, potentially dropping certificate restrictions such as force-command after a second factor succeeded. Returning non-nil Permissions with PartialSuccessError now results in a connection error.
Improper Preservation of Permissions
SSH Agent Constraint-Serialization Bug (v<0.52.0)
CVE-2026-39832
8.7 - High
- May 22, 2026
When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.
Improper Preservation of Permissions
Unbound <1.25.1 DoS via Excess EDNS Options
CVE-2026-41292
7.5 - High
- May 20, 2026
NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data structures for the options. Coordinated attacks can result in degradation and/or denial of service. Unbound 1.25.1 contains a patch with a fix to limit acceptable incoming EDNS options (100).
Inefficient Algorithmic Complexity
RCE via Insecure Deserialization in APScheduler JSON/CBOR ser (4.0.0a5)
CVE-2026-31072
8.8 - High
- May 19, 2026
The JSONSerializer and CBORSerializer in APScheduler (all versions including 3.10.x and 4.0.0a5) are vulnerable to Remote Code Execution (RCE) via Insecure Deserialization. The unmarshal_object function allows for arbitrary class instantiation and state injection by dynamically importing modules and calling __setstate__ on any class available in the Python environment. An attacker can exploit this by submitting a specially crafted JSON or CBOR payload to an application using these serializers
Marshaling, Unmarshaling
urllib3 2.6.0-<2.7.0 Decompress Whole Response DoS via Brotli
CVE-2026-44432
7.5 - High
- May 13, 2026
urllib3 is an HTTP client library for Python. From 2.6.0 to before 2.7.0, urllib3 could decompress the whole response instead of the requested portion (1) during the second HTTPResponse.read(amt=N) call when the response was decompressed using the official Brotli library or (2) when HTTPResponse.drain_conn() was called after the response had been read and decompressed partially (compression algorithm did not matter here). These issues could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This could result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data) on the client side. This vulnerability is fixed in 2.7.0.
Data Amplification
Stay on top of Security Vulnerabilities
Want an email whenever new vulnerabilities are published for Red Hat Openstack or by Red Hat? Click the Watch button to subscribe.
