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Blind SSRF in Keycloak X.509 authenticator via CRL and OCSP URLs

Priority LOW 18CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-918 and the CVSS impact.

Summary

The X.509 client-certificate authenticator in Keycloak fetches CRL Distribution Points or OCSP URLs when revocation checks are enabled. An unauthenticated remote attacker can supply a crafted certificate that makes Keycloak send outbound requests to internal or external endpoints before validation completes, a blind server-side request forgery (CWE-918).

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

A flaw was found in the X.509 client-certificate authenticator of Keycloak, a solution for identity and access management. The issue occurs when the server is configured to check certificate revocation using CRL Distribution Points or OCSP. An attacker can provide a specially crafted certificate that points to a malicious server, causing Keycloak to make unauthorized outbound requests to internal or external endpoints before the certificate is fully validated. This can lead to a blind server-side request forgery (SSRF) attack.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0012 1st percentileScored 2026-10-21
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red HatRed Hat Build of Keycloak——No fix listedCNA
Red HatRed Hat Build of Keycloak——No fix listedCNA
Red HatRed Hat Single Sign-On 7——Not affectedCNA
  • Red Hat Build of Keycloak VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Build of Keycloak VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Single Sign-On 7 VendorRed Hat Affected — Fixed in — Not affected CNA

CPE names CNA · 2

CPEVersionsRoleVendor
cpe:/a:redhat:build_keycloak:——Red Hat
cpe:/a:redhat:red_hat_single_sign_on:77—Red Hat
  • cpe:/a:redhat:build_keycloak: Versions — — ·Red Hat
  • cpe:/a:redhat:red_hat_single_sign_on:7 Versions 7 — ·Red Hat

Remediation

The sources list no fixed version for Red Hat Build of Keycloak. Red Hat rates this Moderate and gives no fix plan for Red Hat Build of Keycloak. Red Hat Single Sign-On 7 is not affected.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Build of KeycloakAffectedNo fix yet
Not affected: 1 product
  • Red Hat Single Sign-On 7

Timeline

  1. 2026-10-05 Threatist record created from CVE-2026-105301
  2. 2026-10-05 Alias added: GHSA-hg66-m76j-q2rm
  3. 2026-10-05 Affected versions changed · Red Hat
  4. 2026-10-05 CVSS score added · Red Hat

References

  • TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
  • TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
See all 7413 →

Sources