CVE-2026-11900

What is known

The Ad Inserter – Ad Manager & AdSense Ads plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to and including 2.8.16 via the 'data' attribute of the [adinserter] shortcode. This is due to the replace_ai_tags() function processing a {reusable-block-N} tag pattern that calls get_post_field('post_content', N) without verifying the requesting user's capability with current_user_can('read_post'), without restricting the post type to 'wp_block', and without checking the post status. This makes it possible for authenticated attackers, with Contributor-level access and above, to read the full content of arbitrary posts including Private, Draft, Pending, Trashed, and password-protected posts owned by other users, by placing the shortcode in a post they own and previewing it.

Business impact

Successful exploitation of CVE-2026-11900, a medium vulnerability (CVSS 4.3) affecting the affected product, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether the affected product is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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