dbcve.org
Better Auth\/ssoApplication · Better Auth

CVE-2026-53515

HIGH · 7.1 CVSS v3.1 Published 2026-07-15
Fix available
A fix is available. Upgrade to 1.6.11 or later.
See remediation →
77/100
Remediation priority · High
Remotely reachable Zero-click 5 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The @better-auth/sso plugin's POST /sso/register endpoint has an authorization bypass where registerSSOProvider only checks for organization membership but fails to verify the user has owner or admin privileges. This allows any organization member to register attacker-controlled OIDC or SAML SSO providers, which can then use the /sso/callback/{providerId} endpoint to provision malicious organizations.

MitigationUpgrade to Better Auth version 1.6.11 or later which adds proper role verification to the registerSSOProvider function.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Better Auth\/ssoApplication
Affected:< 1.6.11
Better AuthApplication
Affected:>= 1.2.10, < 1.6.11

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Better Auth version
    Check your package.json or node_modules/@better-auth/core/package.json for the version field, or run `npm list @better-auth/core` or `npm list better-auth`
    Affected if version is >= 1.2.10 and < 1.6.11, or the @better-auth/sso plugin version is < 1.6.11
  2. Verify SSO plugin is enabled
    Inspect your Better Auth configuration to confirm the sso plugin is imported and initialized in your auth instance
    Affected if the sso plugin from @better-auth/sso is installed and configured in your application
  3. Confirm organization feature is in use
    Check your Better Auth configuration for the organization plugin (org: orgPlugin) being enabled, as the vulnerability requires organization membership to exploit
    Affected if the organization plugin is enabled and users can belong to organizations
  4. Review SSO provider registrations
    Examine your database or admin configuration for any SSO provider registrations, particularly any providers that were not intentionally created by admin/owner users
    Affected if there are SSO providers registered that were not created by users with owner or admin privileges

Your environment is affected if you are running Better Auth or @better-auth/sso with versions between 1.2.10 and 1.6.11 (exclusive), have the SSO plugin enabled, and use the organization feature where unprivileged members could register SSO providers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.6.11 or later
Fixed in 1.6.11
Interim mitigation

Upgrade to Better Auth version 1.6.11 or later which adds proper role verification to the registerSSOProvider function.

Recommended fix High confidence

1.6.11

  1. Check current better-auth and @better-auth/sso versions by running `npm list better-auth @better-auth/sso` or checking package.json
  2. Update to version 1.6.11 by running `npm install [email protected] @better-auth/[email protected]` or `npm install @better-auth/sso@latest`
  3. Verify the upgrade was successful by checking the installed version with `npm list`
  4. Test that the SSO registration endpoint now properly enforces owner/admin role requirements for adding SSO providers

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Better Auth\/sso Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53515 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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