Improper verification of cryptographic signature in JSON Web Signatures - CVE-2025-65945
Published: January 19, 2026
Vulnerability identifier: #VU121638
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-65945
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Auth0
Affected software:
JSON Web Signatures
JSON Web Signatures
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass authorization checks.
The vulnerability exists due to improper signature verification under specific conditions when using the HS256 algorithm within the jws.createVerify() function. A remote attacker can manipulate header or payload in the HMAC secret lookup routines and bypass authorization checks.
How to mitigate CVE-2025-65945
Install updates from vendor's website.