Executive brief
e107 is a content management system used to build and manage websites. A security flaw allows any logged-in user to modify or overwrite comments posted by other users. This could lead to the spread of misinformation, harassment, or damage to the website's reputation as user-contributed content can no longer be trusted as authentic.
Technical details
A broken access control vulnerability (Insecure Direct Object Reference) exists in e107 CMS prior to version 2.3.4. The application's comment editing logic in `comment.php` and the `updateComment` function in `comment_class.php` failed to verify if the requesting user was the original author of the comment. An attacker with a low-privileged account can exploit this by sending a POST request to `comment.php?mode=edit` with a manipulated `itemid` parameter. Because the server-side SQL query originally only filtered by `comment_id` without checking `comment_author_id`, the attacker can successfully overwrite any comment in the database. This issue is resolved in version 2.3.4 by adding an ownership check to the database update query.
Affected products
- e107inc e107 < 2.3.4
Timeline
- 2026-05-05: advisory: GitHub Security Advisory published by the vendor
- 2026-05-26: disclosed: CVE published to the NVD
- 2026-05-26: patched: Fix released in version 2.3.4