What is CVE-2026-4338?

CVE-2026-4338 is a high-severity vulnerability in Automattic Activitypub, classified under CWE-200 INFORMATION EXPOSURE. CVSS score: 7.5/10. Published 2026-04-08.

How severe is CVE-2026-4338?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Automattic Activitypub

CVE-2026-4338

The ActivityPub WordPress plugin before 8.0.2 does not properly filter posts to be displayed, allowed unauthenticated users to access drafts/scheduled/pending posts

EPSS: 0.004 (27.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Automattic Activitypub
Unknown Activitypub — versions 0

References

contact@wpscan.com (technical-description, Third Party Advisory, exploit, vdb-entry)

Frequently asked questions

What is CVE-2026-4338?: CVE-2026-4338 is a high-severity vulnerability in Automattic Activitypub, classified under CWE-200 INFORMATION EXPOSURE. CVSS score: 7.5/10. Published 2026-04-08.
How severe is CVE-2026-4338?: High severity. CVSS v3 base score is 7.5 out of 10.