CVE-2026-3906 | WordPress 6.9 - 6.9.1 - Missing Authorization to Authenticated (Subscriber+) Arbitrary Note Creation via REST API

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.

Published: 2026-03-11 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-3906 is rated Low Risk (23.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.25%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-3906

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.02% 0.25% +0.23%
2 2026-03-11 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-3906

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]

Weakness enumeration for CVE-2026-3906

OS Trackers for CVE-2026-3906

vendor priority summary link
debian unimportant CVE-2026-3906 unimportant priority: Debian including 1 source packages (wordpress), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-3906
ubuntu medium CVE-2026-3906 medium priority: Ubuntu including 1 source packages (wordpress), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 7, released 1. https://ubuntu.com/security/CVE-2026-3906

Affected software / configurations for CVE-2026-3906

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-3906

cvelogic Threat Intelligence