CVE-2026-10513
Description
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.
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| pfefferle Webmention | v ≤ 5.8.0 | — |
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