peter bassill · operator
$ cve CVE-2025-59934 JSON

CVE-2025-59934

9.4
CRITICAL · CVSS 3.1 · EPSS 8.1% (pctl 95)

In your normal cycle

Critical by CVSS (9.4), but no sign of active exploitation.

Description

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.

Scoring

CVSS9.4 (CRITICAL, v3.1)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
EPSS8.07% — more likely to be exploited than 95% of all CVEs
WeaknessCWE-287
On CISA KEVno
Public exploitnone known
Published2025-09-26
Last modified2026-06-17

References

→ the Explorer  ·  watch your stack  ·  NVD