CVE-2026-4366 Keycloak-services: blind server-side request forgery (ssrf) via http redirect handling in keycloak
Attackers can exploit improper HTTP redirect handling in Keycloak to access internal resources and cloud metadata, leading to information disclosure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-4366?
CVE-2026-4366 is a medium-severity server-side request forgery vulnerability in Redhat Build of Keycloak, published on 18 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-918
Which versions are affected by CVE-2026-4366?
It affects 4 products.
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-2026-4366?
No fix has been published for CVE-2026-4366 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-4366 being exploited?
There is no known exploitation of CVE-2026-4366 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 GHSA-g2qr-3mxm-86jj.