CVE-2026-95503

Description

A flaw was found in the Kerberos federation provider of Keycloak, an open-source identity and access management solution. When Kerberos password authentication is used without SPNEGO, the system fails to verify the identity of the Key Distribution Center (KDC) by requesting a server ticket. This allows an attacker on the same network to spoof the KDC and bypass the authentication process, potentially gaining unauthorized access to user accounts.

Overview

State: PUBLISHED
Assigner (CNA): redhat
CVSS severity: MEDIUM
CVSS score: 6.8 / 10
CVSS vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Effective score: 6.8 / 10 MEDIUM source: CNA overview
CWE(s): CWE-347
Reserved: 2026-09-22
Published: 2026-09-22 07:43 UTC
Last updated: 2026-09-22 14:36 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/95xxx/CVE-2026-95503.json

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-09-22 08:16:43 UTC
NVD last modified: 2026-09-22 19:37:36 UTC
NVD CVSS v3.1: 6.8 / 10 MEDIUM source: secalert@redhat.com
NVD CVSS vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Exploitability subscore: 1.6 / 10
Impact subscore: 5.2 / 10
EPSS score: 0.0013 (probability of exploitation in next 30 days)
EPSS percentile: 3.03% vs all CVEs — higher = more likely to be exploited, as of 2026-09-23

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-84288
Assigner: redhat
Published: Sep 22, 2026, 7:43:29 AM
Updated: Sep 22, 2026, 2:36:35 PM
EUVD base score (CVSS 3.1): 6.8 / 10
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
EUVD-reported EPSS: 0.1300
Aliases: GHSA-35j3-ccrv-pgvj

ENISA description: A flaw was found in the Kerberos federation provider of Keycloak, an open-source identity and access management solution. When Kerberos password authentication is used without SPNEGO, the system fails to verify the identity of the Key Distribution Center (KDC) by requesting a server ticket. This allows an attacker on the same network to spoof the KDC and bypass the authentication process, potentially gaining unauthorized access to user accounts.

EUVD references (2)

Affected products (4)

Vendor	Product	Versions	Platforms
Red Hat	Red Hat Build of Keycloak	—	—
Red Hat	Red Hat Build of Keycloak	—	—
Red Hat	Red Hat Build of Keycloak	—	—
Red Hat	Red Hat Single Sign-On 7	—	—

Vendor references (2)

References embedded in the original CVE record by the assigning CNA.

https://access.redhat.com/security/cve/CVE-2026-95503 vdb-entryx_refsource_REDHAT
RHBZ#2537744 issue-trackingx_refsource_REDHAT

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

NVD-tagged references (2)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://access.redhat.com/security/cve/CVE-2026-95503 secalert@redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2537744 secalert@redhat.com

Remediations (10)

CVE-2026-95503 - Red Hat Customer Portal

web:access.redhat.com

Overall, you have the following options: Upgrade to a supported product version that includes a fix for this vulnerability (recommended). Apply a mitigation (if one exists). Customers with the Technical Account Manager (TAM) RHEL Security Select Add-on can review this CVE directly with their TAM.

2026-09-24 11:45 UTC
CVE-2026-95503 — CVSS 6.8 MEDIUM | CTIWatch

web:ctiwatch.com

Technical Analysis CVE-2026-95503 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments. The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

2026-09-24 11:45 UTC
CVE-2026-95503: Red Hat Vulnerability (CVSS 6.8) | CVETodo

web:cvetodo.com

CVE-2026-95503 is a CVSS 6.8 medium-severity vulnerability in Red Hat products. Full technical analysis, mitigations , and exploit status — updated in real time.

2026-09-24 11:45 UTC
CVE-2026-95503 - Exploits & Severity - Feedly

web:feedly.com

Timeline Highlight events Vendor advisory RedHat CVE advisory released a security advisory ( CVE-2026-95503 ).

2026-09-24 11:45 UTC
Microsoft Patch Tracker (September 2026): Exploit-Ranked | Senserva

web:senserva.com

Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.

2026-09-24 11:45 UTC
CVE-2026-95503 - Keycloak Kerberos Federation Bypass Allows…

web:vulmon.com

Keycloak Kerberos Federation Bypass Allows KDC Spoofing. An attacker on the same network may spoof the Key Distribution Center (KDC) and bypass authentication…

2026-09-24 11:45 UTC
Oracle Critical Patch Update Advisory - July 2026

web:www.oracle.com

This Critical Patch Update contains 1448 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at July 2026 Critical Patch Update: Executive Summary and Analysis.

2026-09-24 11:45 UTC
CVE-2026-95503: Red Hat Build of Keycloak Vulnerability

web:www.strix.ai

How severe is CVE-2026-95503 ? CVE-2026-95503 has a CVSS score of 6.8/10 (MEDIUM severity). How do I fix CVE-2026-95503 ? Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

2026-09-24 11:45 UTC
CVE-2026-95503 | Tenable®

web:www.tenable.com

A flaw was found in the Kerberos federation provider of Keycloak, an open-source identity and access management solution. When Kerberos password authentication is used without SPNEGO, the system fails to verify the identity of the Key Distribution Center (KDC) by requesting a server ticket. This allows an attacker on the same network to spoof the KDC and bypass the authentication process ...

2026-09-24 11:45 UTC
Patch Tuesday September 2026: Security Updates & CVE Analysis

web:zecurit.com

Get the complete breakdown of Microsoft's September 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

2026-09-24 11:45 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-95503.json.

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