Red Hat Product Errata RHSA-2026:76128 - Security Advisory
Issued:
2026-10-05
Updated:
2026-10-05

RHSA-2026:76128 - Security Advisory

Synopsis

Important: Red Hat Single Sign-On 7.6.13 security update on RHEL 7

Type/Severity

Security Advisory: Important

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Identify and remediate systems affected by this advisory.

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Topic

New Red Hat Single Sign-On 7.6.13 packages are now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of none. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Red Hat Single Sign-On 7.6 is a standalone server, based on the Keycloak project, that provides authentication and standards-based single sign-on capabilities for web and mobile applications.

This release of Red Hat Single Sign-On 7.6.13 on RHEL 7 serves as a replacement for Red Hat Single Sign-On 7.6.12, and includes bug fixes and enhancements, which are documented in the Release Notes document linked to in the References.

Security Fix(es):

  • undertow-core: Undertow MadeYouReset HTTP/2 DDoS Vulnerability (CVE-2025-9784)
  • Undertow HTTP Server Fails to Reject Malformed Host Headers Leading to Potential Cache Poisoning and SSRF (CVE-2025-12543)
  • Undertow HTTP Server Fails to Reject Malformed Host Headers Leading to Potential Cache Poisoning and SSRF (CVE-2025-12543)
  • Information disclosure and data deletion via second-order SQL injection (CVE-2026-0603)
  • GOSTCTR implementation unable to process more than 255 blocks correctly (CVE-2025-14813)
  • PKIX draft CompositeVerifier accepts empty signature sequence as valid (CVE-2026-5588)
  • unbounded PGP AEAD chunk size leads to pre-auth resource exhaustion (CVE-2026-3505)
  • High integrity impact due to improper DNS domain name constraint enforcement (CVE-2026-42579)
  • HTTP Request Smuggling due to improper handling of conflicting HTTP/1.0 headers (CVE-2026-42581)
  • HTTP Header Injection via HttpProxyHandler Disabled Validation (CVE-2026-42578)
  • Denial of Service via unbounded memory allocation in HTTP content decompression (CVE-2026-42587)
  • Denial of Service via unbounded memory allocation in HTTP content decompression (CVE-2026-42587)
  • IPv6 subnet rule bypass due to incorrect masking operation (CVE-2026-44249)
  • Denial of Service via malformed HAProxy message (CVE-2026-44893)
  • Denial of Service due to resource leak (CVE-2026-48043)
  • Netty HAProxy PROXY protocol v2 codec: Denial of Service via memory leak from crafted PROXY protocol headers (CVE-2026-48059)
  • Netty has Insufficient Bailiwick Validation for NS Records (CVE-2026-47691)
  • Improper trust manager handling leads to hostname verification bypass (CVE-2026-50010)
  • Information disclosure and data manipulation due to improper CNAME record validation (CVE-2026-45674)
  • Denial of Service due to eager buffer allocation in TLS handshake (CVE-2026-45416)
  • Arbitrary code execution via PolymorphicTypeValidator bypass (CVE-2026-54512)
  • Denial of Service via deeply nested JSON processing (CVE-2026-50193)
  • Denial of Service via incomplete fix in async JSON parser (CVE-2026-68494)
  • Missing authentication on EAP's IIOP NameService leads to MITM or DoS (CVE-2026-15563)
  • Session fixation in OIDC login flow that can lead to account takeover (CVE-2026-7507)
  • Denial of Service via specially crafted SAML input (CVE-2026-7307)
  • Denial of Service due to excessive SAMLRequest decompression (CVE-2026-2575)
  • Denial of Service via excessive processing of OpenID Connect scope parameters (CVE-2026-4634)
  • Unauthorized access via improper validation of encrypted SAML assertions (CVE-2026-2092)

For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section.

Solution

Before applying this update, make sure all previously released errata relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

  • Red Hat Single Sign-On 7.6 for RHEL 7 x86_64

Fixes

(none)

Red Hat Single Sign-On 7.6 for RHEL 7

SRPM
rh-sso7-keycloak-18.0.20-1.redhat_00001.1.el7sso.src.rpm SHA-256: e6f5bdd0ca0af117173065476a483441a5732b0d4baa23ba8d2b9bb36426c069
x86_64
rh-sso7-keycloak-18.0.20-1.redhat_00001.1.el7sso.noarch.rpm SHA-256: 2e25f957a334caf0e06bf7dff69e8f2cce7b58d4f7580f519a05aeb82866062c
rh-sso7-keycloak-server-18.0.20-1.redhat_00001.1.el7sso.noarch.rpm SHA-256: 7c1a86ca68e7c6f0a57f6a077618da91a28ad0e9f8bade6a3fb632d97c0640ee

The Red Hat security contact is secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.