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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 03 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


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

{'score': 2, 'vector': '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-03T19:32:01.754Z

Reserved: 2026-07-18T12:38:41.077Z

Link: CVE-2025-71402

cve-icon Vulnrichment

Updated: 2026-08-03T19:31:57.219Z

cve-icon NVD

Status : Received

Published: 2026-08-01T13:16:55.510

Modified: 2026-08-03T20:16:41.720

Link: CVE-2025-71402

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-02T03:30:14Z

Weaknesses