The Filter Gallery WordPress plugin fails to verify the nonce in several AJAX handlers when the field is omitted and performs no capability check. As a result, users with a Subscriber role or lower can overwrite the content of arbitrary posts and delete the plugin’s stored gallery options. This flaw is a classic example of CWE‑284 where improper authorization allows unauthorized data modification, which can compromise site content and user trust. The vulnerability does not grant arbitrary code execution but enables malicious editing of published material and erosion of plugin configuration.

Any WordPress installation running the Filter Gallery plugin older than version 1.1.5 is affected. The plugin, marked as Unknown:Filter Gallery, does not patch this flaw until the 1.1.5 release and later. Sites that rely on this plugin for image galleries or content display are at risk if still on a vulnerable version.

The CVSS score of 7.1 classifies this weakness as high severity, while the EPSS score of less than 1 % suggests a currently low probability of real‑world exploitation. The vulnerability is not listed in CISA’s KEV catalog. Exploitation requires only that a user be authenticated as a Subscriber or lower and send a crafted AJAX request; no special privileges or network access are needed beyond normal site login. Once the request is accepted, the attacker can overwrite any post and remove stored gallery options, potentially leading to widespread content tampering across the site. Given the ease of exploitation for low‑privilege accounts and the lack of mitigation, the risk remains significant and warrants prompt action.