CVE-2023-5057: Automattic Activitypub

Medium severity, CVSS 5.4. EPSS: 0.5% chance of exploitation in the next 30 days.

The ActivityPub WordPress plugin before 1.0.0 does not escape user metadata before outputting them in mentions, which could allow users with a role of Contributor and above to perform Stored XSS attacks

Affected products

• Automattic Activitypub: before 1.0.0 (fixed in 1.0.0)

Published 2023-10-16. Last modified 2026-06-17.