Critical (9.1) in python-jwt project python-jwt. EPSS 5.3% chance of exploitation in the next 30 days. Fixed in python-jwt 3.3.4.
python-jwt is a module for generating and verifying JSON Web Tokens. Versions prior to 3.3.4 are subject to Authentication Bypass by Spoofing, resulting in identity spoofing, session hijacking or authentication bypass. An attacker who obtains a JWT can arbitrarily forge its contents without knowing the secret key. Depending on the application, this may for example enable the attacker to spoof other user's identities, hijack their sessions, or bypass authentication. Users should upgrade to version 3.3.4. There are no known workarounds.
Severity
CVSS 3.1
9.1 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
5.3% chance of exploitation in the next 30 days; higher than 92% of CVEs (scores of 2026-10-31)