CVE-2026-4874

Summary

A flaw was found in Keycloak. An authenticated attacker can perform Server-Side Request Forgery (SSRF) by manipulating the client_session_host parameter during refresh token requests. This occurs when a Keycloak client is configured to use the backchannel.logout.url with the application.session.host placeholder. Successful exploitation allows the attacker to make HTTP requests from the Keycloak server’s network context, potentially probing internal networks or internal APIs, leading to information disclosure.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat build of Keycloak 26.426.4.13-1 < *unaffected
Red HatRed Hat build of Keycloak 26.426.4-19 < *unaffected
Red HatRed Hat build of Keycloak 26.426.4-19 < *unaffected
Red HatRed Hat build of Keycloak 26.626.6.3-3 < *unaffected
Red HatRed Hat build of Keycloak 26.626.6-6 < *unaffected
Red HatRed Hat build of Keycloak 26.626.6-6 < *unaffected

Weaknesses

  • CWE-918: Server-Side Request Forgery (SSRF)

Workarounds

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References