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Fencer Vulns
medium 6.8

CVE-2026-95503 json

Keycloak-services: keycloak-services: potential kdc spoofing bypass when kerberos password authentication is enabled

published 2026-09-22 48 d ago modified 2026-11-06 2 d ago also EUVD-2026-84288

cvss
6.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-95503 updated cvss 6.8

keycloak-services: keycloak-services: Potential KDC spoofing bypass when Kerberos password authentication is enabled

  • Red Hat Single Sign-On 7 keycloak-services 18.0.19.redhat-00002
    affected: workaround, no fix available “Fix deferred”
  • Red Hat build of Keycloak 26.6.8
    fixed: vendor fix RHSA-2026:95761

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
47 d ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.8 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

  • Red Hat Red Hat build of Keycloak 26.6.8
  • Red Hat Red Hat Single Sign-On 7

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.