CVEvulnerability
CVE-2026-53518
7.6 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-07-15
- Last modified
- 2026-07-21
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 7.6 HIGH — CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/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
- CVSS 3.1 ([email protected])
- 8.1 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-362, CWE-367
Description
Better Auth is an authentication and authorization library for TypeScript. From 1.6.0 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint for the authorization_code grant redeems a single-use authorization code through a non-atomic find-then-delete sequence, allowing two concurrent requests to pass the read step and mint independent access tokens, refresh tokens, and ID tokens; legacy /oauth2/token and /mcp/token paths in oidc-provider and mcp plugins share the same primitive. This issue is fixed in version 1.6.11.
Affected configurations
• better-auth better-auth\/oauth-provider (>= 1.6.0 < 1.6.11)
• better-auth better auth (>= 1.6.0 < 1.6.11)