Vulnerability · Published Jul 15, 2026 · Assigned by GitHub_M

CVE-2026-53515Better Auth: Privilege escalation via SSO provider registration: missing admin role check in @better-auth/sso

High 7.1

In plain English

A high-severity privilege mismanagement 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 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.1High

Exploit odds (30 days)0.4%top 63.0% 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. From 1.2.10 until 1.6.11, the @better-auth/sso plugin's POST /sso/register endpoint lets any organization member attach a new SSO provider to that organization because registerSSOProvider checks only for a membership row and does not require an owner or admin role, allowing attacker-controlled OIDC or SAML providers to drive /sso/callback/{providerId} organization provisioning. 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-gv74-j8m3-fg5f

Affected products (as reported)

Vendor	Product	Versions
better-auth	better-auth	>= 1.2.10, < 1.6.11
@better-auth	sso	>= 1.2.10, < 1.6.11

Weakness: CWE-269, CWE-285, CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

References

https://github.com/better-auth/better-auth/security/advisories/GHSA-gv74-j8m3-fg5f x_refsource_CONFIRM
https://github.com/better-auth/better-auth/pull/9220 x_refsource_MISC
https://github.com/better-auth/better-auth/commit/86765f1597378f5c3deed1b80ca91faac0a6bf00 x_refsource_MISC
https://github.com/better-auth/better-auth/releases/tag/v1.6.11 x_refsource_MISC