CVE-2026-4874
Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation
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.
How to fix CVE-2026-4874
No fixed version has been published yet. Mitigate by removing the affected package or applying upstream guidance from the references below.
- —no fix listed
Is CVE-2026-4874 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, <= 26.6.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | LOW3.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N |