CVE-2026-12408

What is known

The Slim SEO – A Fast & Automated SEO Plugin For WordPress plugin for WordPress is vulnerable to Unauthorized Private Content Disclosure in all versions up to, and including, 4.9.8 via the `/wp-json/slim-seo/meta-tags/ai` REST API endpoint. This is due to the endpoint's `permission_callback` performing only a top-level `edit_posts` capability check without verifying that the requesting user has read access to the specific post supplied via the `object.ID` parameter, allowing the `generate` function to pass the attacker-controlled post ID to `Data::get_post_content()`, which calls `get_post()` regardless of post status or ownership. This makes it possible for authenticated attackers with Contributor-level access and above to retrieve AI-generated summaries of the raw `post_content` of arbitrary posts they are not authorized to view — including private posts, drafts, pending, future, and password-protected content authored by other users — with the substance of the protected content disclosed via the HTTP response.

Business impact

Successful exploitation of CVE-2026-12408, 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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