Executive brief
Filter Gallery is a popular WordPress plugin for creating image galleries. The plugin fails to validate security tokens (nonces) on several administrative functions when the token is missing, and does not check user permissions properly. This allows lower-privileged users to overwrite the content of any post on the site and delete the plugin's gallery settings, potentially disrupting site content and configuration.
Technical details
The vulnerability is a broken access control issue (CWE-284) in the Filter Gallery WordPress plugin versions before 1.1.5. Multiple AJAX handlers implement a fail-open nonce verification mechanism: when the nonce parameter is omitted, the validation is skipped entirely rather than being rejected. Combined with the absence of capability checks, this allows any authenticated user (subscriber level and above) to invoke sensitive actions. An attacker can craft AJAX requests to overwrite arbitrary post content or delete plugin options without the required permissions or CSRF protection. The issue requires network access and authentication but no user interaction. Patches are available in version 1.1.5 and later.
Affected products
- WordPress Filter Gallery before 1.1.5
Timeline
- 2026-09-16: disclosed
- 2026-09-18: patched: Fixed in version 1.1.5