PT-2026-53940 · Pfefferle · Webmention

Volodymyr Kolesnykov · Published 2026-06-30 · Updated 2026-06-30 · CVE-2026-10513

NVD

CVSS v3.1

7.2

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

The Webmention plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 5.8.0 via parser-derived 'avatar' and 'url' author metadata. This is due to insufficient input sanitization and output escaping on user-supplied MF2 author properties processed by the unauthenticated webmention REST endpoint and rendered directly into HTML 'value' attributes by the edit-comment-form template without esc attr() or esc url(). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a privileged user (moderator or administrator) opens the affected comment edit screen.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-10513

Affected Products

Webmention

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2026-10513 · Security Note
• https://plugins.trac.wordpress.org/browser/webmention/tags/5.7.0/includes/handler/class-mf2.php#L129 · Note
• https://plugins.trac.wordpress.org/changeset/3583033/webmention · Note
• https://plugins.trac.wordpress.org/browser/webmention/tags/5.7.0/templates/edit-comment-form.php#L15 · Note
• https://wordfence.com/threat-intel/vulnerabilities/id/5a4e144a-3c84-4da3-8fa6-e5fe9c897efe?source=cve · Note