CVE-2025-71402 json
better-auth before 1.4.0 Session Revocation via Forged Cookie
published 2025-11-26 11 mo ago modified 2026-10-06 33 d ago also EUVD-2025-210584 , GHSA-wmjr-v86c-m9jj
- cvss
- 2.0
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 19%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm better-auth 1.4.0
- better-auth better-auth 1.4.0
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 2.0 | 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 |
| CNA | 4.0 | 2.0 | 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 |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | better-auth | >=1.3.34, <1.4.0 |
1.4.0 |
Affected products
- better-auth better-auth
Classification
References
-
github.com
/better-auth/better-auth/commit/cfc453a2a6eb02951f9a0a7c944064936e73eee8
web
-
github.com
/better-auth/better-auth/security/advisories/GHSA-wmjr-v86c-m9jj
vendor-advisory, web
-
vulncheck.com
/advisories/better-auth-before-session-revocation-via-forged-cookie
third-party-advisory
-
github.com
/better-auth/better-auth
package
-
github.com
/better-auth/better-auth/releases/tag/v1.4.0
web
Sources
- CVE List CVE-2025-71402
- GitHub Advisory GHSA-wmjr-v86c-m9jj
- NVD CVE-2025-71402
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.