vulnerability / NVI-00017620 / Revision 1
Better Auth has stored XSS in the auth-server origin via javascript: redirect_uri in oidc-provider and mcp
GitHub lists this reviewed advisory for better-auth, better-auth. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
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.
7.7 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
source listed< 1.6.13
### Am I affected? Check each condition. Users are affected when all of the first three hold. - Their application enables the `oidc-provider` plugin or the `mcp` plugin from `better-auth/plugins`. The `mcp` plugin wraps the same provider and carries the same defect. Both are on the migration path to `@better-auth/oauth-provider`, which is not affected. - Their application `better-auth` version is `1.6.12` or earlier on the stable line, or any `1.7.0-beta` build on the pre-release line. Both release lines carry the same defect. - Their application consent page is a client component that reads `redirectURI` from the `authClient.oauth2.consent(...)` response and assigns it to a browser navigation target such as `window.location.href`, `location.assign`, or `location.replace`. Two conditions raise an application's exposure: - It sets `allowDynamicClientRegistration: true`. Client registration is then unauthenticated, so any visitor can plant the malicious client. The default is `false`, which limits planting to authenticated users. - It exposes the consent page to ordinary end users rather than to a restricted operator audience. A developer's application is not affected when any o
better-auth
source listed>= 1.7.0-beta.0, < 1.7.0-beta.4
### Am I affected? Check each condition. Users are affected when all of the first three hold. - Their application enables the `oidc-provider` plugin or the `mcp` plugin from `better-auth/plugins`. The `mcp` plugin wraps the same provider and carries the same defect. Both are on the migration path to `@better-auth/oauth-provider`, which is not affected. - Their application `better-auth` version is `1.6.12` or earlier on the stable line, or any `1.7.0-beta` build on the pre-release line. Both release lines carry the same defect. - Their application consent page is a client component that reads `redirectURI` from the `authClient.oauth2.consent(...)` response and assigns it to a browser navigation target such as `window.location.href`, `location.assign`, or `location.replace`. Two conditions raise an application's exposure: - It sets `allowDynamicClientRegistration: true`. Client registration is then unauthenticated, so any visitor can plant the malicious client. The default is `false`, which limits planting to authenticated users. - It exposes the consent page to ordinary end users rather than to a restricted operator audience. A developer's application is not affected when any o
03 / Response
What to do next
- 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.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-86j7-9j95-vpqj ↗
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.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.