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Fencer Vulns
medium 6.5

CVE-2026-105306 json

Keycloak-services: keycloak-services: token introspection audience bypass via dynamic client registration

published 2026-10-05 35 d ago modified 2026-10-12 28 d ago also EUVD-2026-92258

cvss
6.5
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 12%
public exploits
0
none known

Summary

A flaw was found in the Dynamic Client Registration flow of the Keycloak identity and access management server. The issue occurs because the registration process fails to filter security-sensitive client attributes when a new client is created. An attacker with a valid Initial Access Token can register a client that bypasses audience checks during token introspection. This allows the attacker to view sensitive identity information, roles, and session details from access tokens belonging to other applications in the same realm.

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-2026-105306 updated cvss 6.5

keycloak-services: keycloak-services: Token introspection audience bypass via Dynamic Client Registration

  • Red Hat Build of Keycloak rhbk/keycloak-rhel9, keycloak-services 26.6.7.redhat-00003
    affected: workaround, no fix available
  • Red Hat Single Sign-On 7 keycloak-services 26.6.7.redhat-00003
    not affected: vulnerable code not present

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
partial
Assessed
35 d ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

  • Red Hat Red Hat Build of Keycloak
  • Red Hat Red Hat Single Sign-On 7

Classification

Weakness

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.