CVE-2026-28802

Estado: ModificadaAlta (7.7)—

Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7.

CVSS

Versión: 4.0
Vector: 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:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Puntuación base: 7.7

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.57%
Percentil entre todas las CVEs puntuadas: 45
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access85 %
Impacto principalT1553.006 Code Signing Policy Modificationdefense impairment80 %

Authlib acepta tokens JWT con alg:none sin verificación remota (AV:N, PR:N, UI:N). Impacto: falsificación de certificados/tokens (T1553.006) por bypass de validación criptográfica.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account Management Vulnerability Scanning Restrict Registry Permissions Network Segmentation Limit Access to Resource Over Network Filter Network Traffic

Tecnologías afectadas (1)

Authlib — Authlib

CWE

CWE-347
CWE-347

Referencias

JSON original (NVD)

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