PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-53515 better-auth CVE debrief

The CVE record for CVE-2026-53515 was published on 2026-07-15T18:16:47.817Z. 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. This issue is fixed in version 1.6.11. Users of Better Auth's @better-auth/sso plugin from version 1.2.10 to 1.6.10 should apply the patch to prevent authentication bypass attacks.

Vendor
better-auth
Product
Unknown
CVSS
HIGH 7.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-15
Original CVE updated
2026-07-21
Advisory published
2026-07-15
Advisory updated
2026-07-21

Who should care

Users of Better Auth's @better-auth/sso plugin from version 1.2.10 to 1.6.10, operators of affected systems, and security teams should apply the patch to prevent authentication bypass attacks. They should review compensating controls for exposed systems while remediation is scheduled and verified.

Technical summary

The @better-auth/sso plugin's POST /sso/register endpoint allows any organization member to attach a new SSO provider without requiring an owner or admin role. This enables attacker-controlled OIDC or SAML providers to drive organization provisioning via /sso/callback/{providerId}. The issue is fixed in version 1.6.11. Affected product deployments should be reviewed for exposure, and compensating controls should be implemented while remediation is scheduled and verified.

Defensive priority

Apply the patch to prevent authentication bypass attacks.

Recommended defensive actions

  • Apply the patch by upgrading to version 1.6.11
  • Verify and limit organization membership
  • Monitor for suspicious SSO provider registrations
  • Implement compensating controls for SSO provider management
  • Review affected product deployments in managed environments
  • Track exceptions and retest remediated assets

Evidence notes

The CVE record and NVD detail provide information on the vulnerability and patch. The vendor has released a patch in version 1.6.11. Evidence limits suggest that the @better-auth/sso plugin's vulnerability allows any organization member to attach a new SSO provider without requiring an owner or admin role, enabling attacker-controlled OIDC or SAML providers to drive organization provisioning via /sso/callback/{providerId}. Defenders should verify affected product deployments, review official advisories, and plan vendor-supported updates or mitigations.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-53515 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-53515

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-53515 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-53515

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.