The Webform module allows site builders to create forms, collect submissions, and configure access to forms and submission data. When Webform is used with JSON...

An authenticated user may be able to view another user's webform submission data because JSON:API can return a response cached for a different user. This requires JSON:API to be enabled, the affected webform to expose submissions through JSON:API, and the attacker to have permission to view their own submissions for that webform.

Find drupal/webform and its version in composer.lock. The advisory lists fixes in 6.2.12 and 6.3.1, but gives no affected version range. Check whether JSON:API is enabled, whether the webform exposes submissions through JSON:API, and whether authenticated users have permission to view their own submissions for that webform.

The advisory says the vulnerability is mitigated by requiring JSON:API to be enabled, the affected webform to expose submissions through JSON:API, and the attacker to have an account with permission to view their own submissions for that webform.

The Webform module allows site builders to create forms, collect submissions, and configure access to forms and submission data.

When Webform is used with JSON:API enabled, submissions may be cached without varying correctly by the authenticated user. If a webform is configured so that authenticated users can view their own submissions, a request to the JSON:API webform submission collection can return a cached response generated for a different user.

This can allow an authenticated user to view another user's webform submission data through the JSON:API collection endpoint.

This vulnerability is mitigated by the fact that JSON:API must be enabled, the affected webform must expose submissions through JSON:API, and the attacker must have an account with permission to view their own submissions for the affected webform.