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CVE-2026-43914

Estado: AnalizadaCrítica (9.8)—

Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to 1.35.4, there is a security vulnerability in Vaultwarden that allows bypassing the login brute-force protection if email 2fa is enabled. If email 2fa is enabled, the unprotected 2fa-function send_email_login (email.rs, api endpoint /api/two-factor/send-email-login) also acts as an oracle determining whether a username-password combination is correct. An attacker can abuse that endpoint to brute-force passwords without rate-limiting. This works even for users who don't have email 2fa configured. This vulnerability is fixed in 1.35.4.

CVSS

Probabilidad de explotación (EPSS)

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.

AV:N/AC:L/PR:N permite explotación remota sin autenticación (T1190). El endpoint /api/two-factor/send-email-login carece de rate-limiting, permitiendo ataque de fuerza bruta contra contraseñas (T1110.001) para obtener acceso a cuentas (T1078.001).

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

Password PoliciesMulti-factor AuthenticationUpdate SoftwareVulnerability ScanningPrivileged Account ManagementNetwork Segmentation

Tecnologías afectadas (1)

Dani-garcia — Vaultwarden

CWE

Referencias

JSON original (NVD)

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