Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refresh_token grant authenticates only possession of…
| CVE ID | CVE-2026-53512 |
| Vendor | Unknown Vendor |
| Affected Product | Unknown Product |
| Vulnerability Type | Vulnerability |
| CVSS Score | 9.1 (CRITICAL) |
| EPSS Score | 0.3% probability of exploitation in the next 30 days |
| Actively Exploited | ❌ No known exploitation |
| Patch Status | Pending Vendor Disclosure |
| Reported By | CYBERDUDEBIVASH SENTINEL APEX Intelligence (via sentinel_apex) |
Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refresh_token grant authenticates only possession of the bound refreshToken row and matching client_id, without verifying the confidential client's client_secret, allowing an attacker with a valid refresh_token to mint access tokens and rotated refresh tokens through /api/auth/oauth2/token or /api/auth/mcp/token. The @better-auth/oauth-provider package is not affected. This issue is fixed in version 1.6.11.
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