Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

CVE-2025-61920

Gravedad CVSS v3.1:
ALTA
Tipo:
CWE-20 Validación incorrecta de entrada
Fecha de publicación:
10/10/2025
Última modificación:
03/11/2025

Descripción

*** Pendiente de traducción *** Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.5, Authlib’s JOSE implementation accepts unbounded JWS/JWT header and signature segments. A remote attacker can craft a token whose base64url‑encoded header or signature spans hundreds of megabytes. During verification, Authlib decodes and parses the full input before it is rejected, driving CPU and memory consumption to hostile levels and enabling denial of service. Version 1.6.5 patches the issue. Some temporary workarounds are available. Enforce input size limits before handing tokens to Authlib and/or use application-level throttling to reduce amplification risk.

Productos y versiones vulnerables

CPE Desde Hasta
cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:* 1.6.5 (excluyendo)