The Block Editor Gallery Slider plugin for WordPress contains a missing capability check on the classic_gallery_slider_options() function in all releases up to version 1.1.1, allowing authenticated users with Subscriber-level access or higher to modify certain post meta fields for arbitrary posts. This flaw enables attackers to alter the content or configuration of posts without permission, leading to data integrity violations and potentially exposing sensitive or design information to unauthorised parties.

The vulnerability affects the krasenslavov Block Editor Gallery Slider for WordPress – Image Slider, Gallery Carousel & Lightbox Plugin. All plugin versions up to and including 1.1.1 are impacted. Users running any of these releases on their WordPress site are at risk unless they upgrade the plugin.

This issue has a CVSS score of 4.3 and an EPSS score of less than 1%, indicating a moderate severity with a very low probability of exploitation. The vulnerability is not listed in CISA’s KEV catalog. Attackers must be authenticated and possess at least Subscriber privileges, so the attack vector is authenticated. The missing authorization check exposes a small subset of post metadata but does not provide remote code execution or full post deletion capabilities.