# CVE-2026-53513

## Summary

- **CVE ID:** CVE-2026-53513
- **Severity:** CRITICAL
- **CVSS Score:** 9.6 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N)
- **CWE:** CWE-20, CWE-345, CWE-441, CWE-918
- **Published:** Jul 15, 2026
- **Last Modified:** Jul 15, 2026

## Description

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the @better-auth/sso plugin's POST /sso/register and POST /sso/update-provider endpoints accept attacker-controlled oidcConfig.userInfoEndpoint, tokenEndpoint, and jwksEndpoint URLs when skipDiscovery: true is set, store them on the ssoProvider row without origin validation, and fetch them during OIDC callback, allowing non-blind server-side request forgery and possible account linking when trustEmailVerified: true is configured. This issue is fixed in version 1.6.11.

## Affected Products

- better-auth — better-auth (>= 0.1.0, < 1.6.11)
- @better-auth — sso (>= 0.1.0, < 1.6.11)

## References

- [CNA](https://github.com/better-auth/better-auth/security/advisories/GHSA-5rr4-8452-hf4v)
- [CNA](https://github.com/better-auth/better-auth/pull/9574)
- [CNA](https://github.com/better-auth/better-auth/commit/37f60cb176cb53147da7dfd5ec15afa5b486e81e)
- [CNA](https://github.com/better-auth/better-auth/releases/tag/v1.6.11)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.25%
- **EPSS Percentile:** 16.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._