WordPress Webmention plugin <= 5.8.0 - Unauthenticated Stored Cross-Site Scripting vulnerability

Unauthenticated Stored Cross-Site Scripting vulnerability discovered by Volodymyr Kolesnykov in WordPress Plugin Webmention versions = 5.8.0...

CVE-2026-10513

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...

CVE-2026-10513 Webmention <= 5.8.0 - Unauthenticated Stored Cross-Site Scripting via MF2 'photo'/'url' Author Properties

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...

CVE-2026-10513 Webmention <= 5.8.0 - Unauthenticated Stored Cross-Site Scripting via MF2 'photo'/'url' Author Properties

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...

CVE-2026-10513

CVE-2026-10513 affects the WordPress Webmention plugin (versions up to and including 5.8.0). The root cause is insufficient input sanitization and output escaping for MF2 author properties (avatar/url) processed by the unauthenticated webmention REST endpoint and rendered into HTML value attribut...

EUVD-2026-40376

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...

CVE-2026-10513

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...

PT-2026-53940

Name of the Vulnerable Software and Affected Versions Webmention versions prior to 5.8.1 Description Stored Cross-Site Scripting occurs due to insufficient input sanitization and output escaping of user-supplied Microformat 2 MF2 author properties. An unauthenticated attacker can inject arbitrary...

CVE-2026-10513: Improper Neutralization of Input During Web Page Generation

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...

CVE-2026-42180

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controll...

CVE-2026-42180

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controll...

CVE-2026-42180 Lemmy: SSRF in /api/v3/post via Webmention dispatch

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controll...

CVE-2026-42180

Lemmy prior to version 0.19.18 is affected by a server-side request forgery: an authenticated low-privilege user can create a link post via POST /api/v3/post, and when posted to public communities Lemmy dispatches a Webmention to the target. The code path only validates the URL’s syntax/scheme (h...

CVE-2026-42180 Lemmy: SSRF in /api/v3/post via Webmention dispatch

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controll...

CVE-2026-42180

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controll...

CVE-2026-42180 Lemmy: SSRF in /api/v3/post via Webmention dispatch

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controll...

EUVD-2026-28819

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controll...

CVE-2026-42180: Server-Side Request Forgery (SSRF)

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controll...

GHSA-3JVJ-V6W2-H948 Lemmy has SSRF in /api/v3/post via Webmention dispatch

Summary Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controlled link target. The submitted URL is checked for syntax and scheme, but th...

Lemmy has SSRF in /api/v3/post via Webmention dispatch

Summary Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controlled link target. The submitted URL is checked for syntax and scheme, but th...