@better-auth/oauth-provider may provide access tokens for unauthorized audiences via unbound resource indicators

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.4 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

EPSS

• CVE-2026-67332: 0.26% estimated exploitation activity in the next 30 days; percentile 17.74 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Am I affected? Users are affected if all of the following hold: - Their application depends on @better-auth/oauth-provider on any stable 1.6.x release (the stable line is not patched) or on a pre-release before 1.7.0-beta.4. - Their application either configures validAudiences with more than one audience, or it issues JWT access tokens whose aud (resource) claim is consumed by their resource servers. - Their resource servers make authorization decisions based on that aud or resource value. A deployment with a single validAudiences entry (or the default, their server's base URL) cannot mint a token for a different audience. The provider rejects any resource outside the allowlist. Such a deployment still does not bind the resource to the authorization grant, so the spec-compliance gap remains even where cross-audience escalation does not apply. Fix: 1. Upgrade to @better-auth/oauth-provider@1.7.0-beta.4 (then 1.7.0), then run the schema migration (npx auth migrate). This is a breaking…

Published by the source

7 Jul 2026, 20:54 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 12:56 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-p2fr-6hmx-4528

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-p2fr-6hmx-4528

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# Patch Next advisory brief: CVE-2026-67332

Advisory: @better-auth/oauth-provider may provide access tokens for unauthorized audiences via unbound resource indicators
IDs: CVE-2026-67332, GHSA-p2fr-6hmx-4528
Record: https://patchnext.com/advisories/cve-2026-67332 (revision 2, source checked 26 Oct 2026, 12:56 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @better-auth/oauth-provider 1.7.0-beta.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @better-auth/oauth-provider: affected >= 1.4.8, < 1.7.0-beta.4; fixed in 1.7.0-beta.4

## Suggested inspection (read-only)
- `npm ls @better-auth/oauth-provider --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @better-auth/oauth-provider.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-p2fr-6hmx-4528 (OSV record GHSA-p2fr-6hmx-4528 lists affected ranges: npm @better-auth/oauth-provider >=1.4.8 <1.7.0-beta.4 (fixed))
- Verified: https://github.com/advisories/GHSA-p2fr-6hmx-4528 (GitHub-reviewed advisory GHSA-p2fr-6hmx-4528 lists affected ranges: npm @better-auth/oauth-provider >=1.4.8 <1.7.0-beta.4)

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