SSRF in @Better-Auth Sso

CVE-2026-53513

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.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.002 (15.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-53513?
CVE-2026-53513 is a critical-severity vulnerability in @Better-Auth Sso, classified under Improper Input Validation. CVSS score: 9.6/10. Published 2026-07-15.
How severe is CVE-2026-53513?
Critical severity. CVSS v3 base score is 9.6 out of 10.