Improper Verification of Cryptographic Signature in Keycloak - CVE-2026-1529
Published: September 10, 2026
Vulnerability identifier: #VU148915
CSH Severity: Medium
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-1529
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to gain unauthorized access to an organization.
The vulnerability exists due to improper verification of cryptographic signatures in Keycloak invitation token validation when processing a modified invitation token JSON Web Token payload. A remote user can modify the organization ID and target email in a legitimate invitation token to gain unauthorized access to an organization.
Affected software
Keycloak
Red Hat build of Keycloak
Red Hat build of Keycloak
How to mitigate CVE-2026-1529
Install security update from vendor's website.
Keycloak - addressed in versions 26.2.13, 26.4.9, 26.5.3
Red Hat build of Keycloak - addressed in versions 26.2.13, 26.4.9
Red Hat build of Keycloak - addressed in versions 26.2.13, 26.4.9