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Fencer Vulns
medium 5.8

CVE-2026-4366 json

Keycloak-services: blind server-side request forgery (ssrf) via http redirect handling in keycloak

published 2026-03-18 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-12762

cvss
5.8
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 15%
public exploits
0
none known

Summary

A flaw was identified in Keycloak, an identity and access management solution, where it improperly follows HTTP redirects when processing certain client configuration requests. This behavior allows an attacker to trick the server into making unintended requests to internal or restricted resources. As a result, sensitive internal services such as cloud metadata endpoints could be accessed. This issue may lead to information disclosure and enable attackers to map internal network infrastructure.

Patch / fix

  • Red Hat Red Hat build of Keycloak 26.4 26.4-17, 26.4.12-1

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-2026-4366 updated cvss 5.8

keycloak-services: Blind Server-Side Request Forgery (SSRF) via HTTP Redirect Handling in Keycloak

  • Red Hat Build of Keycloak rhbk/keycloak-rhel9-operator, 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 26.4-17, rhbk/keycloak-rhel9-operator 26.4-17, rhbk/keycloak-operator-bundle 26.4.12-1
    fixed: vendor fix RHSA-2026:19597
  • Red Hat build of Keycloak 26.4.12
    fixed: vendor fix RHSA-2026:19596

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
yes
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

Affected products

  • Red Hat Red Hat build of Keycloak 26.4
  • Red Hat Red Hat build of Keycloak 26.4.12
  • 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.