Reported vulnerability

Slim SEO <= 4.9.8 - Authenticated (Contributor+) Insufficient Authorization to Private Content Disclosure via 'object.ID' Parameter

Q: Which versions of Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated are affected?

Wordfence lists these affected versions: Start version unspecified, through 4.9.8. Use the version checker above to compare your installed release with this report.

Q: Is a fix available for Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated?

Wordfence reports a fix for this issue in Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated. It lists these fixed versions: 4.9.9. Back up your website and test the recommended update before applying it to your live site.

Q: Where can I find my installed plugin version?

In WordPress, open Plugins > Installed Plugins and find the version shown beneath the plugin name.

Published 30 Jun 2026

Updated 1 Jul 2026

CVE-2026-12408

Compare your installed software with the affected versions below. Follow the source’s remediation guidance and test an available update after taking a backup. A database entry describes a reported issue; it does not establish whether a particular website has been compromised.

Does this affect my version?

Check your installed version against this advisory. This compares the report’s version ranges and does not scan your website.

Wordfence advisory

medium · CVSS 4.3

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.

Severity vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated

Software: plugin · slim-seo
Affected versions: Start version unspecified, through 4.9.8
Fix availability: Fix available
Fixed versions: 4.9.9

Recommended action

Update to version 4.9.9, or a newer patched version

Further references (1)

wordfence.com/threat-intel/vulnerabilities/id/6e6603a0-8f35-49fb-a517-ba6344538c4d?source=api-prod

Data sources and licences

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CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.

Read licence terms

Source: Wordfence

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Questions about this vulnerability

Which versions of Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated are affected?

Wordfence lists these affected versions: Start version unspecified, through 4.9.8. Use the version checker above to compare your installed release with this report.

Is a fix available for Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated?

Wordfence reports a fix for this issue in Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated. It lists these fixed versions: 4.9.9. Back up your website and test the recommended update before applying it to your live site.

Where can I find my installed plugin version?

In WordPress, open Plugins > Installed Plugins and find the version shown beneath the plugin name.

Does an affected version mean my website has been hacked?

An affected version means the installed release matches a vulnerability described in this report. It does not show whether anyone has exploited it on your website. The checker compares version numbers with stored reports; it does not inspect your website.

These reports cover at least one of the same plugins, themes or WordPress core. Check each report’s affected versions separately.

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