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Fencer Intel
medium 6.8

CVE-2026-95503 json

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

published last mo. modified 5d 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.

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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
last mo.

Exploit prediction

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

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 Intel 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.