CVE-2026-3906

WordPress 6.9 - 6.9.1 - Missing Authorization to Authenticated (Subscriber+) Arbitrary Note Creation via REST API

2026-03-10 00:00
kaminuma

Strategic Overview

Status
Patched in 6.9.2
Affected Core
WordPress 6.9
Affected Version
6.9 – 6.9.1
CVSS
4.3Medium
Weakness type
CWE-862 · Missing Authorization
CVE
CVE-2026-3906
View all WordPress 6.9 vulnerabilities

At a glance

CVE-2026-3906 is a medium-severity Missing Authorization vulnerability in the WordPress 6.9 WordPress release line, affecting 6.9 – 6.9.1. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 6.9.2; sites on affected versions should update now. Disclosed March 2026, reported by kaminuma.

Vulnerability Overview

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.

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-862: Missing Authorization

WordPress 6.9 6.9 – 6.9.1 carries this weakness at create_item_permissions_check(), and reaching it takes an account at Subscriber level or above. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.

Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For WordPress 6.9 the fix is 6.9.2: builds 6.9 – 6.9.1 are affected, anything from 6.9.2 onward is not.

Remediation

Update to version 6.9.2, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: updating to 6.9.2 is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C