CVE-2026-10513

HIGH 7.2

Webmention <= 5.8.0 - Unauthenticated Stored Cross-Site Scripting via MF2 'photo'/'url' Author Properties

CVSS Score

7.2

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-79
Vendor	pfefferle
Product	webmention
Published	Jun 30, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

Affected Versions

pfefferle / Webmention

0 ≤ 5.8.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/5a4e144a-3c84-4da3-8fa6-e5fe9c897efe?source=cve plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/webmention/tags/5.7.0/templates/edit-comment-form.php#L15 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/webmention/tags/5.7.0/includes/handler/class-mf2.php#L129 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/changeset/3583033/webmention

Credits

Volodymyr Kolesnykov