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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| better-auth | better-auth | unaffected |
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Fixes
Solution
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References
History
Sat, 01 Aug 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | better-auth before 1.4.0 Session Revocation via Forged Cookie | |
| First Time appeared |
Better-auth
Better-auth better-auth\/oauth-provider |
|
| Weaknesses | CWE-347 | |
| CPEs | cpe:2.3:a:better-auth:better-auth\/oauth-provider:*:*:*:*:*:node.js:*:* | |
| Vendors & Products |
Better-auth
Better-auth better-auth\/oauth-provider |
|
| References |
| |
| Metrics |
cvssV4_0
|
Projects
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MITRE
Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-08-01T12:22:16.655Z
Reserved: 2026-07-18T12:38:41.077Z
Link: CVE-2025-71402
Vulnrichment
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NVD
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Redhat
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Weaknesses