CVE-2025-65015: fallo crítico en authlib joserfc
joserfc has Possible Uncontrolled Resource Consumption Vulnerability Triggered by Logging Arbitrarily Large JWT Token Payloads
Publicada el · Actualizada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
28Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 9.2epss 0.4%
joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. In versions from 1.3.3 to before 1.3.5 and from 1.4.0 to before 1.4.2, the ExceededSizeError exception messages are embedded with non-decoded JWT token parts and may cause Python logging to record an arbitrarily large, forged JWT payload. In situations where a misconfigured — or entirely absent — production-grade web server sits in front of a Python web application, an attacker may be able to send arbitrarily large bearer tokens in the HTTP request headers. When this occurs, Python logging or diagnostic tools (e.g., Sentry) may end up processing extremely large log messages containing the full JWT header during the joserfc.jwt.decode() operation. The same behavior also appears when validating claims and signature payload sizes, as the library raises joserfc.errors.ExceededSizeError() with the full payload embedded in the exception message. Since the payload is already fully loaded into memory at this stage, the library cannot prevent or reject it. This issue has been patched in versions 1.3.5 and 1.4.2.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
Productos afectados
authlib · joserfcCVEs relacionadas — authlib joserfc
En el mismo producto, de las más peligrosas a las menos.
CVE-2026-27932HIGHjoserfc PBES2 p2c Unbounded Iteration Count enables Denial of Service (DoS)EPSS 0.5%CVE-2026-48990MEDIUMjoserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserializationEPSS 0.2%CVE-2026-119283HIGHjoserfc: Unbounded JWE General JSON `recipients` Array Leads to CPU Exhaustion (DoS) via Repeated RSA Private-Key DecryptionEPSS 0.2%CVE-2026-119284MEDIUMjoserfc: Compact JWS size guard allocates attacker-controlled segments before rejectionEPSS 0.2%CVE-2026-49852HIGHjoserfc: HS256/HS384/HS512 verify accepts empty/nil HMAC key (cross-language sibling of CVE-2026-45363)EPSS 0.2%CVE-2026-62995LOWjoserfc accepts JWT with padding, leading to JWT malleabilityEPSS 0.1%
Referencias
https://github.com/authlib/joserfc/commit/63932f169d924caffafa761af2122b82059017f7https://github.com/authlib/joserfc/commit/673c8743fd0605b0e1de6452be6cba75f44e466bhttps://github.com/authlib/joserfc/releases/tag/1.3.5https://github.com/authlib/joserfc/releases/tag/1.4.2https://github.com/authlib/joserfc/security/advisories/GHSA-frfh-8v73-gjg4