CVE-2025-71402
better-auth before 1.4.0 Session Revocation via Forged Cookie
- State
- Published
- Severity
- 2.0 Low
- Published
- Aug 1, 2026
- Updated
- Aug 3, 2026
- Reserved
- Jul 18, 2026
Description
better-auth versions greater than 1.3.34 and before 1.4.0 contain a vulnerability in the multi-session plugin's /sign-out after-hook, which trusts raw multi-session cookies and forwards extracted values to internalAdapter.deleteSessions without verifying the cookie signature (e.g., via getSignedCookie). An attacker can supply a forged _multi-* cookie to trigger deletion of arbitrary session tokens.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 2.0 Low | CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:N | VulnCheck |
Weaknesses
- CWE-347 Improper Verification of Cryptographic Signature
Affected Products
| Product | Versions |
|---|---|
better-authbetter-auth |
|
References
- GitHub Security Advisory (GHSA-wmjr-v86c-m9jj)vendor-advisory
- VulnCheck Advisory: better-auth before 1.4.0 Session Revocation via Forged Cookiethird-party-advisory
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