CVE-2026-53515

high

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.

References

https://github.com/better-auth/better-auth/security/advisories/GHSA-gv74-j8m3-fg5f

https://github.com/better-auth/better-auth/releases/tag/v1.6.11

https://github.com/better-auth/better-auth/pull/9220

https://github.com/better-auth/better-auth/commit/86765f1597378f5c3deed1b80ca91faac0a6bf00

Details

Source: Mitre, NVD

Published: 2026-07-15

Updated: 2026-07-15

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:C/A:N

Severity: High

CVSS v3

Base Score: 7.1

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

Severity: High

EPSS

EPSS: 0.00028