#VU117881 Resource exhaustion in authlib - CVE-2025-61920
Published: October 31, 2025
Vulnerability identifier: #VU117881
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-61920
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
authlib
authlib
Software vendor:
Authlib
Authlib
Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to the way the Authlib's JOSE implementation handles untrusted input. A remote non-authenticated attacker can send overly large amount of data via unbounded JWS/JWT header and signature segments to the application and consume memory and CPU resources, leading to a denial of service condition.
Remediation
Install updates from vendor's website.