Account takeover via unsigned password-reset tokens
Published Sep 26, 2025 · Updated Sep 26, 2025
Improper JWT verification in Formbricks before 4.0.1 allows remote attackers to take over accounts through forged password-reset tokens. The shared verifyToken routine in apps/web/lib/jwt.ts calls jwt.decode instead of verifying the signature, expiry, issuer, or audience. Knowledge of a victim's user.id is required; an unsigned token then reaches the reset action and changes that account's password without prior authentication.
Summary
What happened
Improper JWT verification in Formbricks before 4.0.1 allows remote attackers to take over accounts through forged password-reset tokens. The shared verifyToken routine in apps/web/lib/jwt.ts calls jwt.decode instead of verifying the signature, expiry, issuer, or audience. Knowledge of a victim's user.id is required; an unsigned token then reaches the reset action and changes that account's password without prior authentication.
The record
- CVE
- CVE-2025-59934
- Published
- Sep 26, 2025
- Updated
- Sep 26, 2025
- Vendor
- Formbricks
- Product
- Formbricks
- Classifications
- CWE-347, CWE-287, CWE-345, T1098
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 26, 2025CVE publishedPublication date reported by the CVE source.
- Sep 26, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 4.0.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA unsigned JWT password-reset proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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