CVEvulnerability
CVE-2026-11800
8.1 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-06-25
- Last modified
- 2026-10-25
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 8.1 HIGH — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CVSS 3.1 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)
- 8.1 HIGH — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-347
Description
A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an attacker with valid client credentials to bypass signature verification. By forging an assertion, the attacker can create unauthorized access tokens. This enables the attacker to impersonate any federated user linked to the affected Identity Provider, leading to unauthorized access and potential privilege escalation.
Affected configurations
• redhat build of keycloak (>= 26.6 < 26.6.4)
Related
Weakness · CWE (1)
- CWE-347 Improper Verification of Cryptographic Signature weakness
References
- https://access.redhat.com/errata/RHSA-2026:30083 Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:30084 Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-11800 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2487006 Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:30083 Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:30084 Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-11800 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2487006 Vendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-11800.json Vendor Advisory