CVE-2026-53515

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

State: Published
Severity: 7.1 High
Published: Jul 15, 2026
Updated: Jul 15, 2026
Reserved: Jun 9, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.1 High	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N	GitHub_M

Weaknesses

CWE-269 Improper Privilege Management
CWE-285 Improper Authorization
CWE-863 Incorrect Authorization

Affected Products

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

References

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