Improper Verification of Cryptographic Signature in Red Hat build of Keycloak - CVE-2026-9793
Published: September 11, 2026
Vulnerability identifier: #VU148992
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-9793
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to submit unauthorized claims in the OIDC authorization flow.
The vulnerability exists due to improper verification of cryptographic signatures in JWE-encrypted request object processing when processing a JWE-encrypted request object with raw JSON plaintext. A remote attacker can submit a JWE-encrypted request object with raw JSON plaintext to submit unauthorized claims in the OIDC authorization flow.
Affected software
Red Hat build of Keycloak
How to mitigate CVE-2026-9793
Install security update from vendor's website.
Red Hat build of Keycloak - update to 26.6.5