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vulnerability / NVI-00016136 / Revision 1

Better Auth: OAuth refresh-token rotation forks the token family on concurrent redemption

GitHub lists this reviewed advisory for @better-auth/oauth-provider, better-auth. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.

source listedactiveGHSA-392p-2q2v-4372CVE-2026-53517

This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.

01 / Meaning

Why it matters

Published affected context helps an owner decide what evidence to gather. This report has not examined your application.

CVSS

8.1 high

GitHub source severity; exploitability and local consequence require separate evidence.

As of · GitHub Advisory Database

02 / Applicability

The affected context

Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.

@better-auth/oauth-provider

source listed
  • >= 1.6.0, < 1.6.11

### Am I affected? Users are affected if all of the following are true: - Their project depends on `@better-auth/oauth-provider` at a version `>= 1.6.0, = 1.4.8-beta.7, < 1.6.0`. - At least one OAuth client served by their application's authorization server requests the `offline_access` scope, so refresh tokens are minted. - Concurrent redemption of the same refresh token is reachable: an SPA shares one refresh token across browser tabs without a mutex, a mobile client retries after a transient failure, an attacker who has stolen a refresh token times two requests, or a service worker queues offline requests. If developer applications do not request `offline_access` for any client, no refresh tokens are minted and they are not exposed. Fix: 1. Upgrade to `@better-auth/oauth-provider@1.6.11` or later. 2. If developers cannot upgrade, see workarounds below. ### Summary The OAuth provider's `POST /oauth2/token` endpoint, on the `refresh_token` grant, performs a non-atomic read / validate / revoke / mint sequence on the `oauthRefreshToken` row. Two concurrent requests presenting the same parent refresh token both pass the r

GitHub Advisory Database

better-auth

source listed
  • >= 1.4.8-beta.7, < 1.6.0

### Am I affected? Users are affected if all of the following are true: - Their project depends on `@better-auth/oauth-provider` at a version `>= 1.6.0, = 1.4.8-beta.7, < 1.6.0`. - At least one OAuth client served by their application's authorization server requests the `offline_access` scope, so refresh tokens are minted. - Concurrent redemption of the same refresh token is reachable: an SPA shares one refresh token across browser tabs without a mutex, a mobile client retries after a transient failure, an attacker who has stolen a refresh token times two requests, or a service worker queues offline requests. If developer applications do not request `offline_access` for any client, no refresh tokens are minted and they are not exposed. Fix: 1. Upgrade to `@better-auth/oauth-provider@1.6.11` or later. 2. If developers cannot upgrade, see workarounds below. ### Summary The OAuth provider's `POST /oauth2/token` endpoint, on the `refresh_token` grant, performs a non-atomic read / validate / revoke / mint sequence on the `oauthRefreshToken` row. Two concurrent requests presenting the same parent refresh token both pass the r

GitHub Advisory Database

03 / Response

What to do next

  1. investigate

    Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.

    Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database

A fixed release is not deployment evidence.

Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.

04 / Limits

What this report cannot establish

  • Customer inventory, deployment, reachability and exploitation have not been inspected.
Read the collection and interpretation limits ↗

05 / Provenance

Sources you can inspect

Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.

  1. GHSA-392p-2q2v-4372 ↗

    GitHub Advisory Database · vendor advisory

    Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.

Public revision history

Only published revisions appear here. Routine fetches do not create a material-change event.

  1. Revision 1 ·

    First indexed by Null; source disclosure date is shown separately.

Read the public revision data ↗

The next step is private

Bring the question into your environment.

The connected workflow is a development preview for inventory, contextual matching, owner decisions and evidence-based verification. No system-specific result is generated by this page.

See the synthetic workflow preview ↗