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.
CVSS
No CVSS.
References
Configurations
No configuration.
History
No history.
Information
Published : 2026-08-01 13:16
Updated : 2026-09-08 20:34
NVD link : CVE-2025-71402
Mitre link : CVE-2025-71402
CVE.ORG link : CVE-2025-71402
JSON object : View
Products Affected
No product.
CWE
CWE-347
Improper Verification of Cryptographic Signature
