{"id":"CVE-2026-111109","title":"Webmention <= 5.10.1 - Unauthenticated Stored Cross-Site Scripting via Open Graph og:title Meta Tag","summary":"The Webmention plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Open Graph og:title meta tag of a webmention source URL in versions up to, and including, 5.10.1. This is due to insufficient input sanitization: Me…","severity":"medium","cvss":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","cvssSource":"cna","cwe":["CWE-79"],"vendor":"pfefferle","product":"Webmention","affected":["Webmention <= 5.10.1"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-01T17:34:53.986526Z"},"published":"2026-10-31","updated":"2026-11-01","sourceUpdated":"2026-11-01T17:44:30.159Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-111109","references":[{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/0b283d17-b89f-467d-8a79-cdf7b9bfdb65?source=cve"},{"url":"https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/handler/class-meta.php#L78"},{"url":"https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/entity/class-item.php#L297"},{"url":"https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/class-receiver.php#L453"},{"url":"https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/entity/class-item.php#L125"},{"url":"https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/class-receiver.php#L267"},{"url":"https://github.com/pfefferle/wordpress-webmention/pull/698"},{"url":"https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.2/includes/class-receiver.php"}],"tags":["cve.org"],"epss":0.0028,"epssPercentile":0.20603,"ingestedAt":"2026-11-05T19:30:42.601Z","slug":"CVE-2026-111109","body":"## Overview\n\nThe Webmention plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Open Graph og:title meta tag of a webmention source URL in versions up to, and including, 5.10.1. This is due to insufficient input sanitization: Meta::add_properties() maps og:title to the Item::name property, but Item has no concrete set_name() method, so Item::__call() stores the value raw while sibling set_content()/set_summary() paths route through webmention_sanitize_html(); Item::get_content() then falls back to the raw name when content and summary are empty, and Receiver::process() explicitly removes the core wp_filter_kses / wp_filter_post_kses hooks on pre_comment_content before calling wp_new_comment(), so the payload is persisted to comment_content as-is. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page, after an administrator approves the resulting pending webmention comment. Successful exploitation additionally requires an action by an administrator — the attacker cannot trigger the vulnerability on their own.\n\n## Affected\n\n- `Webmention <= 5.10.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":33.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}