CVE-2025-59934
Formbricks is an open source qualtrics alternative. Prior to version 4.0.1, Formbricks is missing JWT signature verification. This vulnerability stems from a token validation routine that only decodes JWTs (jwt.decode) without verifying their signatures. Both the email verification token login path and the password reset server action use the same validator, which does not check the token’s signature, expiration, issuer, or audience. If an attacker learns the victim’s actual user.id, they can craft an arbitrary JWT with an alg: "none" header and use it to authenticate and reset the victim’s password. This issue has been patched in version 4.0.1.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
- Puntuación base: 9.4
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 8.07%
- Percentil entre todas las CVEs puntuadas: 95
- Fecha de la puntuación: 5/10/2026
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
T1190Exploit Public-Facing Applicationinitial access95 % - Impacto principal
T1078Valid Accountsstealth · persistence · privilege escalation · initial access95 % - Impacto secundario
T1556Modify Authentication Processdefense impairment · persistence · credential access85 %
Vulnerabilidad de verificación faltante en JWT permite autenticación sin firma válida (AV:N, PR:N). Atacante con user.id puede falsificar tokens 'alg: none' para acceso no autorizado (T1078) y control de cuenta (T1098.002).
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)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-287, CWE-345, CWE-347
Referencias
- https://github.com/formbricks/formbricks/blob/843110b0d6c37b5c0da54291616f84c91c55c4fc/apps/web/lib/jwt.ts#L114-L117
- https://github.com/formbricks/formbricks/commit/eb1349f205189d5b2d4a95ec42245ca98cf68c82
- https://github.com/formbricks/formbricks/pull/6596
- https://github.com/formbricks/formbricks/security/advisories/GHSA-7229-q9pv-j6p4
JSON original (NVD)
Mostrar
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"version": "2.0.3",
"timestamp": "2025-09-29T14:59:35.884199Z"
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"published": "2025-09-26T23:15:32.613",
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"descriptions": [
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"value": "Formbricks is an open source qualtrics alternative. Prior to version 4.0.1, Formbricks is missing JWT signature verification. This vulnerability stems from a token validation routine that only decodes JWTs (jwt.decode) without verifying their signatures. Both the email verification token login path and the password reset server action use the same validator, which does not check the token’s signature, expiration, issuer, or audience. If an attacker learns the victim’s actual user.id, they can craft an arbitrary JWT with an alg: \"none\" header and use it to authenticate and reset the victim’s password. This issue has been patched in version 4.0.1."
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"lastModified": "2026-06-17T09:46:52.940",
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