Detections
Analytics
RHEL 8 : Red Hat Single Sign-On 7.6.13 security update on RHEL 8 (Important) (RHSA-2026:76129)
critical Nessus Plugin ID 363126
Synopsis
The remote Red Hat host is missing one or more security updates for Red Hat Single Sign-On 7.6.13.Description
The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:76129 advisory.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.
Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Update the RHEL Red Hat Single Sign-On 7.6.13 package based on the guidance in RHSA-2026:76129.See Also
https://access.redhat.com/errata/RHSA-2026:76129
https://access.redhat.com/security/updates/classification/#important
Plugin Details
Severity: Critical
ID: 363126
File Name: redhat-RHSA-2026-76129.nasl
Version: 1.1
Type: Local
Agent: unix
Family: Red Hat Local Security Checks
Published: 10/6/2026
Updated: 10/6/2026
Supported Sensors: Continuous Assessment, Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 6.5
Percentile: 96.92
Vendor
Vendor Severity: Important
CVSS v2
Risk Factor: Critical
Base Score: 10
Temporal Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS Score Source: CVE-2026-42581
CVSS v3
Risk Factor: Critical
Base Score: 10
Temporal Score: 9
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C
CVSS Score Source: CVE-2026-47691
CVSS v4
Risk Factor: Critical
Base Score: 9.3
Threat Score: 8.4
Threat Vector: CVSS:4.0/E:P
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
CVSS Score Source: CVE-2025-14813
Vulnerability Information
CPE: cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:rh-sso7-keycloak-server, p-cpe:/a:redhat:enterprise_linux:rh-sso7-keycloak
Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu
Exploit Available: true
Exploit Ease: Exploits are available
Patch Publication Date: 10/6/2026
Vulnerability Publication Date: 9/2/2025
Reference Information
CVE: CVE-2025-12543, CVE-2025-14813, CVE-2025-9784, CVE-2026-0603, CVE-2026-15563, CVE-2026-2092, CVE-2026-2575, CVE-2026-3505, CVE-2026-42578, CVE-2026-42579, CVE-2026-42581, CVE-2026-42587, CVE-2026-44249, CVE-2026-44893, CVE-2026-45416, CVE-2026-45674, CVE-2026-4634, CVE-2026-47691, CVE-2026-48043, CVE-2026-48059, CVE-2026-50010, CVE-2026-50193, CVE-2026-54512, CVE-2026-5588, CVE-2026-68494, CVE-2026-7307, CVE-2026-7507