CVE-2025-71402

LOW

better-auth before 1.4.0 Session Revocation via Forged Cookie

Title source: cna
STIX 2.1

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.

References (2)

Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-wmjr-v86c-m9jj)
https://github.com/better-auth/better-auth/security/advisories/GHSA-wmjr-v86c-m9jj
Third Party Advisory third-party-advisory
VulnCheck Advisory: better-auth before 1.4.0 Session Revocation via Forged Cookie
https://www.vulncheck.com/advisories/better-auth-before-session-revocation-via-forged-cookie

Scores

CVSS v4 2.0
EPSS 0.0021
EPSS Percentile 10.8%
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-347
Status published
Products (2)
better-auth/better-auth < 1.4.0
better-auth/better-auth 1.4.0
Published Aug 01, 2026
Tracked Since Aug 01, 2026