Slim SEO <= 4.9.8 - Authenticated (Contributor+) Insufficient Authorization to Private Content Disclosure via 'object.ID' Parameter
Strategic Overview
- Status
- Patched in 4.9.9
- Affected Plugin
- Slim SEO – A Fast & Automated SEO Plugin For WordPress
- Affected Version
<= 4.9.8- CVSS
- 4.3Medium
- Weakness type
- CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor
- CVE
CVE-2026-12408
At a glance
CVE-2026-12408 is a medium-severity Exposure of Sensitive Information to an Unauthorized Actor vulnerability in the Slim SEO WordPress plugin, affecting versions <= 4.9.8. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 4.9.9; sites on affected versions should update now. Disclosed June 2026, reported by Abu Hurayra (HurayraIIT).
Vulnerability Overview
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.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.
CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Slim SEO <= 4.9.8 carries this weakness at get_post_content(), and reaching it takes an account at Contributor level or above. Sensitive information exposure means data the application intended to keep internal is returned to a caller who should not be able to see it.
The disclosed data — credentials, tokens, customer records or internal paths — is usually worth more as material for a follow-up attack than as an end in itself. For Slim SEO the fix is 4.9.9: builds <= 4.9.8 are affected, anything from 4.9.9 onward is not.
Remediation
Update to version 4.9.9, or a newer patched version
How does WordSec protect against this?
The fix is the thing that ends this: Slim SEO 4.9.9 closes this, and updating the plugin is the step that ends it.
- Alerts
External References
Related records
Other vulnerabilities in Slim SEO – A Fast & Automated SEO Plugin For WordPress
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