Auth bypass in Barrykooij Related Posts For WordPress

CVE-2026-109979

The Related Posts for WordPress plugin for WordPress is vulnerable to Sensitive Information Exposure in versions up to, and including, 3.0.0 via the 'rp4wp_create_link' parameter of the hidden 'rp4wp_link_related' admin page. The handle_create_link() handler verifies the nonce and that the current user can edit the parent post, but never checks that the attacker-supplied child post ID is one the user is allowed to read; LinkRepository::insert() stores the arbitrary child ID without validation, and ManageLinks::render() later calls LinkRepository::get_children() in its no-extra-args fast path, which falls through to array_map('get_post', $child_ids) — bypassing read_private_posts/read_post capability checks — and then echoes esc_html($child->post_title) in the parent's editor meta box. This makes it possible for authenticated attackers, with Contributor-level access and above, to read the titles of arbitrary non-public posts (drafts, pending, private, future, trashed) authored by higher-privileged users by linking those post IDs to a draft they own and then reading the resulting meta box.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 22.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-109979?
CVE-2026-109979 is a medium-severity vulnerability in Barrykooij Related Posts For WordPress, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-10-28.
How severe is CVE-2026-109979?
Medium severity. CVSS v3 base score is 4.3 out of 10.