GHSA-WMJR-V86C-M9JJ
Vulnerability from github – Published: 2025-11-26 22:11 – Updated: 2026-05-08 01:19Summary
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.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "better-auth"
},
"ranges": [
{
"events": [
{
"introduced": "1.3.34"
},
{
"fixed": "1.4.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-287",
"CWE-345"
],
"github_reviewed": true,
"github_reviewed_at": "2025-11-26T22:11:50Z",
"nvd_published_at": null,
"severity": "LOW"
},
"details": "### Summary\n\nA 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.",
"id": "GHSA-wmjr-v86c-m9jj",
"modified": "2026-05-08T01:19:47Z",
"published": "2025-11-26T22:11:50Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/better-auth/better-auth/security/advisories/GHSA-wmjr-v86c-m9jj"
},
{
"type": "WEB",
"url": "https://github.com/better-auth/better-auth/commit/cfc453a2a6eb02951f9a0a7c944064936e73eee8"
},
{
"type": "PACKAGE",
"url": "https://github.com/better-auth/better-auth"
},
{
"type": "WEB",
"url": "https://github.com/better-auth/better-auth/releases/tag/v1.4.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "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",
"type": "CVSS_V4"
}
],
"summary": "Better Auth\u0027s multi-session sign-out hook allows forged cookies to revoke arbitrary sessions"
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.