CVE-2025-59934
Prior to version 4.0.1, Formbricks is missing JWT signature verification.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (8.07%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.4 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
- EPSS
- 8.07% probability · 94th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-287, CWE-345, CWE-347
- Source
- security-advisories@github.com
References
- 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.