Formbricks missing JWT signature verification
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| formbricks | formbricks | affected |
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| Vendor | Product | Versions |
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| Formbricks | Formbricks | — |
| Source | ID | Title |
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EUVD |
EUVD-2025-31394 | 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. |
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: 9.5% (9.459% probability within 30 days)
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| Metrics |
ssvc
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| First Time appeared |
Formbricks
Formbricks formbricks |
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| Vendors & Products |
Formbricks
Formbricks formbricks |
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| 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. | |
| Title | Formbricks missing JWT signature verification | |
| Weaknesses | CWE-287 CWE-345 CWE-347 |
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| References |
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| Metrics |
cvssV3_1
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