SA-CONTRIB-2026-292: Critical severity composer/drupal/media_alias_display vulnerability
This module allows for direct viewing of a file with the URL alias. This is a followup advisory to SA-CONTRIB-2026-245, which did not fully resolve the underlying vulnerability. In some cases, files may be served with the HTTP header Cache-Control: public when they should be uncacheable. This can lead to some users getting cached versions of files with information they should not be able to access. This vulnerability is mitigated by the following:
Drupal must be configured to handle non-public files using a custom or contributed module providing an additional file scheme. An attacker must know to request a file that has previously been requested by a more-privileged user, and that file must still be cached.
Credit
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
composer/drupal/media_alias_displayto a version that resolves this vulnerability.Fixed in 3.0.3Fixed in 2.1.3
Event History
Frequently Asked Questions
Which deployments are exposed to this caching issue?
Exposure is limited to Drupal sites configured to handle non-public files through a custom or contributed module that provides an additional file scheme. The affected module is composer/drupal/media_alias_display.
What must happen for an attacker to obtain an improperly cached file?
An attacker must request a file that was previously requested by a more-privileged user and remains in cache. The issue occurs when such files are served with Cache-Control: public despite needing to be uncacheable.
How can administrators determine whether the preconditions exist?
Review whether Drupal uses a custom or contributed module to provide an additional scheme for non-public files, and test the response headers for those files. A response carrying Cache-Control: public for content that should be access-controlled indicates the relevant caching condition.