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Fencer Vulns
low 3.1

CVE-2026-4874 json

Org.keycloak.protocol.oidc.grants: org.keycloak.services.managers: keycloak: server-side request forgery via oidc token endpoint manipulation

published 2026-03-26 7 mo ago modified 2026-09-10 1 mo ago also GHSA-22rm-wp4x-v5cx , EUVD-2026-16142

cvss
3.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 29%
public exploits
0
none known

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.

Patch / fix

  • maven org.keycloak:keycloak-services 26.4.13, 26.6.3
  • Red Hat Red Hat build of Keycloak 26.4 26.4-19, 26.4.13-1
  • Red Hat Red Hat build of Keycloak 26.6 26.6-6, 26.6.3-3

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-2026-4874 updated cvss 3.1

org.keycloak.protocol.oidc.grants: org.keycloak.services.managers: Keycloak: Server-Side Request Forgery via OIDC token endpoint manipulation

  • Red Hat Build of Keycloak rhbk/keycloak-rhel9-operator rhbk/keycloak-rhel9-operator, rhbk/keycloak-operator-bundle rhbk/keycloak-operator-bundle Red Hat JBoss Enterprise Application Platform 8 keycloak-services Red Hat JBoss Enterprise Application Platform Expansion Pack keycloak-services Red Hat Single Sign-On 7 keycloak-services
    affected: workaround, no fix available “Fix deferred”
  • Red Hat build of Keycloak 26.4 rhbk/keycloak-rhel9 26.4-19, rhbk/keycloak-rhel9-operator 26.4-19, rhbk/keycloak-operator-bundle 26.4.13-1
    fixed: vendor fix RHSA-2026:30050
  • Red Hat build of Keycloak 26.4.13
    fixed: vendor fix RHSA-2026:30049
  • Red Hat build of Keycloak 26.6 rhbk/keycloak-rhel9 26.6-6, rhbk/keycloak-rhel9-operator 26.6-6, rhbk/keycloak-operator-bundle 26.6.3-3
    fixed: vendor fix RHSA-2026:25097
  • Red Hat build of Keycloak 26.6.3
    fixed: vendor fix RHSA-2026:25098

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
7 mo ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

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

Affected packages

ecosystem package affected fixed in
maven org.keycloak:keycloak-services
>=26.5.0, <26.6.3
<26.4.13
26.6.3
26.4.13

Affected products

  • Red Hat Red Hat build of Keycloak 26.4
  • Red Hat Red Hat build of Keycloak 26.4.13
  • Red Hat Red Hat build of Keycloak 26.6
  • Red Hat Red Hat build of Keycloak 26.6.3
  • Red Hat Red Hat Build of Keycloak
  • Red Hat Red Hat JBoss Enterprise Application Platform 8
  • Red Hat Red Hat JBoss Enterprise Application Platform Expansion Pack
  • Red Hat Red Hat Single Sign-On 7

Classification

Weakness
  • CWE-918 Server-Side Request Forgery

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.