Authenticated session revocation via forged cookie
Published Aug 1, 2026 · Updated Aug 1, 2026
Session revocation in Better Auth after 1.3.34 and before 1.4.0 allows remote authenticated users to delete arbitrary session tokens. The multi-session /sign-out after-hook passes values from unsigned _multi-* cookies directly to internalAdapter.deleteSessions instead of verifying their signatures. Exploitation requires the multi-session plugin, high privileges, and passive user interaction; successful requests forcibly revoke selected sessions.
Summary
What happened
Session revocation in Better Auth after 1.3.34 and before 1.4.0 allows remote authenticated users to delete arbitrary session tokens. The multi-session /sign-out after-hook passes values from unsigned _multi-* cookies directly to internalAdapter.deleteSessions instead of verifying their signatures. Exploitation requires the multi-session plugin, high privileges, and passive user interaction; successful requests forcibly revoke selected sessions.
The record
- CVE
- CVE-2025-71402
- Published
- Aug 1, 2026
- Updated
- Aug 1, 2026
- Vendor
- Better Auth
- Product
- Better Auth
- Classifications
- CWE-347, T1531
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 1, 2026CVE publishedPublication date reported by the CVE source.
- Aug 1, 2026Record 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=0 <1.4.0
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
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Technologies
Your stack
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Your stack
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