Executive brief
The Webform module for Drupal allows site administrators to build forms and collect user submissions. Due to insufficient validation of export filenames, a user with permission to view submission results can access or delete files from the temporary export directory that belong to other webforms. An attacker must already have legitimate access to view one webform's results and know or guess the target filename, limiting exposure in most deployments.
Technical details
The vulnerability is an insufficient filename validation flaw in the submission export functionality. When serving generated exports, the module does not properly sanitize requested filenames, allowing path traversal or access to unintended files within the configured export temporary directory. An authenticated attacker with webform submission view permissions can exploit this to read or delete arbitrary files in that directory, though they must know or brute-force the target filename. The attack requires existing webform permissions and knowledge of file locations.
Affected products
- Drupal Webform < 6.2.12 or >= 6.3.0 < 6.3.1
Timeline
- 2026-09-23: disclosed: Security advisory SA-CONTRIB-2026-168 published
- 2026-09-23: patched: Fixed in Webform 6.2.12 and 6.3.1