CVE-2026-4874 Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation
Authenticated attackers can perform SSRF via token endpoint manipulation in Keycloak when specific logout configurations are enabled, allowing internal network probing.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-4874?
CVE-2026-4874 is a low-severity server-side request forgery vulnerability in Redhat Build of Keycloak, published on 26 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-918
Which versions are affected by CVE-2026-4874?
4 open source packages ship an affected version, including org.keycloak:keycloak-services. It affects 4 products.
| Package | Affected | Fixed in |
|---|---|---|
org.keycloak:keycloak-services Maven | All versions | 26.4.13 |
org.keycloak:keycloak-services Maven | All versions | 26.4.13 |
org.keycloak:keycloak-services Maven | From 26.5.0 | 26.6.3 |
org.keycloak:keycloak-services Maven | From 26.5.0 | 26.6.3 |
Products include Redhat Build of Keycloak, Redhat Jboss Enterprise Application Platform, Redhat Jboss Enterprise Application Platform Expansion Pack, Redhat Single Sign-On.
How do I fix CVE-2026-4874?
Upgrade org.keycloak:keycloak-services to a fixed version for your release line: 26.4.13 or 26.6.3.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-4874 being exploited?
There is no known exploitation of CVE-2026-4874 in the wild and no public exploit code.
Other vulnerabilities in Redhat Build of Keycloak
- CVE-2026-15572 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation
- CVE-2026-3047 Keycloak SAML Broken has Authentication Bypass by Primary Weakness
- CVE-2026-15573 Keycloak-services: keycloak-services: authorization bypass via unnormalized uri matching in pathmatcher
- CVE-2026-16102 Keycloak-services: keycloak-services: default dcr policy allows role forgery via user property mappers
- CVE-2026-1609 Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users
Sources
Also known as ECHO-1b74-757a-0a67, GHSA-22rm-wp4x-v5cx, MINI-fjg7-pcfc-jg7h, MINI-v6pv-3f3f-2qv5.