Vulnerability · Published Jul 15, 2026 · Assigned by GitHub_M

CVE-2026-53513Better Auth: Server-side request forgery via unvalidated OIDC endpoints on @better-auth/sso provider registration

Critical 9.6

In plain English

A critical-severity improper input validation in better-auth from better-auth. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.6Critical

Exploit odds (30 days)0.2%top 83.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@better-auth/sso	1.6.11	GHSA-5rr4-8452-hf4v

Affected products (as reported)

Vendor	Product	Versions
better-auth	better-auth	>= 0.1.0, < 1.6.11
@better-auth	sso	>= 0.1.0, < 1.6.11

Weakness: CWE-20, CWE-345, CWE-441, CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

References

https://github.com/better-auth/better-auth/security/advisories/GHSA-5rr4-8452-hf4v x_refsource_CONFIRM
https://github.com/better-auth/better-auth/pull/9574 x_refsource_MISC
https://github.com/better-auth/better-auth/commit/37f60cb176cb53147da7dfd5ec15afa5b486e81e x_refsource_MISC
https://github.com/better-auth/better-auth/releases/tag/v1.6.11 x_refsource_MISC