CVE-2026-85237
A vulnerability in MISP's email-based one-time password (OTP) authentication flow allowed an attacker to perform an unrestricted number of OTP verification attempts.
The email_otp() endpoint did not apply brute-force protection when validating submitted OTP values. An attacker who had reached the OTP verification stage, for example after successfully providing a user's primary authentication credentials, could repeatedly submit candidate OTP values while the same OTP remained valid. This significantly increased the feasibility of guessing the OTP and bypassing the additional authentication factor, potentially resulting in unauthorized access to the affected user's account.
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The issue was exacerbated by the fact that the OTP is associated with the user rather than with an individual pending login session, allowing multiple concurrent sessions to attempt guesses against the same valid OTP.
The patch integrates the existing MISP brute-force protection mechanism into the email OTP flow. Failed OTP attempts are now counted against the user, further attempts are rejected once the configured threshold is reached, and the active OTP is invalidated when the attempt budget is exhausted. Blocklisted users are also prevented from requesting the generation of a fresh OTP. In addition, OTP comparison now uses hash_equals() and validates that the submitted value is a string.
CVSS
- Versión: 4.0
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:L/SI:N/SA:N/E:X/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: 8.6
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.46%
- Percentil entre todas las CVEs puntuadas: 38
- 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.
- Explotación
T1210Exploitation of Remote Serviceslateral movement85 % - Impacto principal
T1078.001Default Accountsstealth · persistence · privilege escalation · initial access90 % - Impacto secundario
T1556.006Multi-Factor Authenticationdefense impairment · persistence · credential access75 %
Red sin privilegios (PR:L) tras credenciales válidas, no requiere interacción, acceso remoto: T1210. Impacto principal es acceso no autorizado a cuenta (T1078.001); secundario es manipulación de autenticación multifactor (T1556.006).
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
Tecnologías afectadas (1)
CWE
- CWE-307
Referencias
JSON original (NVD)
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