CVE-2026-53515
Last modified
CVE-2026-53515 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. 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. EPSS estimates a 0.24% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Better-Auth | Better-Auth\/Sso | < 1.6.11 |
| Better-Auth | Better Auth | >= 1.2.10, < 1.6.11 |
References
- https://github.com/better-auth/better-auth/pull/9220Issue Tracking, Patch
- https://github.com/better-auth/better-auth/security/advisories/GHSA-gv74-j8m3-fg5fMitigation, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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