Low severity · published Aug 1, 2026
CVE-2025-71402
better-auth before 1.4.0 Session Revocation via Forged Cookie
2.0
CVSS
0.3%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 19% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BE
better-auth · better-auth
before 1.4.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-71402
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-71402
github.com
https://github.com/better-auth/better-auth/security/advisories/GHSA-wmjr-v86c-m9jj
www.vulncheck.com
https://www.vulncheck.com/advisories/better-auth-before-session-revocation-via-forged-cookie
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