Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation
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.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.keycloak:keycloak-services | >= 26.5.0, < 26.6.3, < 26.4.13 | 26.6.3, 26.4.13 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-4874
- https://github.com/keycloak/keycloak/issues/47935
- https://github.com/keycloak/keycloak/pull/49682
- https://github.com/keycloak/keycloak/pull/49685
- https://github.com/keycloak/keycloak/commit/00dd0dd716c4319d3bac3eb2f2ac22d2a94f79fd
- https://github.com/keycloak/keycloak/commit/63de0efd351a7a684212a042a12271908f63f0ee
- https://access.redhat.com/errata/RHSA-2026:25097
- https://access.redhat.com/errata/RHSA-2026:25098
- https://access.redhat.com/errata/RHSA-2026:30049
- https://access.redhat.com/errata/RHSA-2026:30050
- https://access.redhat.com/security/cve/CVE-2026-4874
- https://bugzilla.redhat.com/show_bug.cgi?id=2451611
- https://github.com/keycloak/keycloak
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N- Weakness (CWE)
CWE-918- Platform
- Java / Kotlin (Maven)
- Package
org.keycloak:keycloak-services- Disclosed
- 26.03.2026
- Updated
- 11.10.2026 13:20
Sources and licenses
OSV / GitHub Advisory Database - GHSA-22rm-wp4x-v5cx - CC BY 4.0
Vulnerability history: org.keycloak:keycloak-services
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 98
- First → latest
- 01.2022 08.2026
- Without a fix
- 16
- Exploited in attacks
- 0
Severity breakdown
- Critical 3
- High 26
- Medium 51
- Low 18
Disclosures per year
- 2022: 9
- 2023: 9
- 2024: 17
- 2025: 11
- 2026: 52
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Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation this entry
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