🛡️ CVE-2025-71402 — better-auth

🟢 CVSS 2.0 — Low ✅ No Known Exploit CWE-287 NVD
2.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Better Auth's multi-session sign-out hook allows forged cookies to revoke arbitrary sessions

Summary

A vulnerability was identified in the multi-session plugin for Better Auth, specifically in the /sign-out after-hook. The hook trusts raw multi-session cookies and forwards the extracted values directly to internalAdapter.deleteSessions without verifying the cookie signature. Because cookie values are not validated with getSignedCookie (or any equivalent check), an attacker can supply a forged _multi-* cookie to trigger deletion of arbitrary session tokens.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs administrative privileges on the target. A user must be tricked into taking some action. Rated impact: confidentiality low, integrity low, availability low.

Weakness class

CVE-2025-71402 is classified as CWE-287: Improper Authentication. The identity of the caller is not established correctly, so an attacker can act as another user.

Affected software

CVE-2025-71402 is recorded against 2 packages.

  • better-auth
  • unknown

Timeline and source

Published on 26 November 2025 and last revised on 2 August 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com (Web)
github.com (Web)
github.com (Package)
github.com (Web)

Details

Severity LOW
CVSS Score 2.0
CVSS 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
CWE CWE-287
Public Exploit ✅ No
Source NVD
Published 2025-11-26
Updated 2026-08-12
Modified 2026-08-02
Fix URL N/A

Affected Packages

Software From version Fixed in
better-auth — —
unknown — —

Similar Threats

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