SSRF in Red Hat Build Of Keycloak
CVE-2026-4874
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (23.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Red Hat Build Of Keycloak
- Red Hat Build Of Keycloak 26.4 — versions 26.4.13-1, 26.4-19
- Red Hat Build Of Keycloak 26.4.13
- Red Hat Build Of Keycloak 26.6 — versions 26.6-8, 26.6-6, 26.6.3-3
- Red Hat Build Of Keycloak 26.6.3
- Red Hat Build Of Keycloak 26.6.4
- Red Hat Jboss Enterprise Application Platform 8
- Red Hat Jboss Enterprise Application Platform Expansion Pack
- Red Hat Single Sign-On 7
- Red Hat Build Of Keycloak
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-4874 (vdb-entry, Vendor Advisory)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Issue Tracking, Vendor Advisory)
- access.redhat.com/errata/RHSA-2026:25098 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:25097 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:30049 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:30050 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-4874?
- CVE-2026-4874 is a low-severity vulnerability in Red Hat Build Of Keycloak, classified under Server-Side Request Forgery (SSRF). CVSS score: 3.1/10. Published 2026-03-26.
- How severe is CVE-2026-4874?
- Low severity. CVSS v3 base score is 3.1 out of 10.