Review reviewCritical

CVE-2026-53513

better-auth better-auth, sso, better-auth/sso

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.

CVSS: 9.6
EPSS: 0.19%
CISA KEV: Not listed
Published: 2026.07.16

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.19%

Technical severityCVSS 9.6

Vulnerability overview

Affected product and versions

Product: better-auth better-auth, sso, better-auth/sso
Affected versions: >= >= 0.1.0, < 1.6.11, >= 0.1.0 < 1.6.11
Fixed versions: 1.6.11

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that better-auth better-auth, sso, better-auth/sso and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

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