Red Hat Security Advisory: Red Hat Single Sign-On 7.6.13 security update on RHEL 8
Affects Red HatSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High : upgrade Red Hat undertow to 2.2.38.Final soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 2.3% chance of exploitation in 30 days – higher than 83% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.2.38.Final
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 2 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade undertow to 2.2.38.Final.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| undertow | Affected
| Fixed in
|
GitHubundertowpkg:github/undertowOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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 8 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.