Auth bypass in WordPress Foundation

CVE-2026-3906

WordPress core is vulnerable to unauthorized access in versions 6.9 through 6.9.1. The Notes feature (block-level collaboration annotations) was introduced in WordPress 6.9 to allow editorial comments directly on posts in the block editor. However, the REST API `create_item_permissions_check()` method in the comments controller did not verify that the authenticated user has `edit_post` permission on the target post when creating a note. This makes it possible for authenticated attackers with Subscriber-level access to create notes on any post, including posts authored by other users, private posts, and posts in any status.

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:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (30.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3906: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3906?
CVE-2026-3906 is a medium-severity vulnerability in WordPress Foundation, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-03-11.
How severe is CVE-2026-3906?
Medium severity. CVSS v3 base score is 4.3 out of 10.