GHSA-98Q7-93HH-5593

Vulnerability from github – Published: 2026-10-31 09:31 – Updated: 2026-10-31 09:31
VLAI
Details

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: 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.

Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2026-111109"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-31T07:16:34Z",
    "severity": "MODERATE"
  },
  "details": "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: 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 \u2014 the attacker cannot trigger the vulnerability on their own.",
  "id": "GHSA-98q7-93hh-5593",
  "modified": "2026-10-31T09:31:12Z",
  "published": "2026-10-31T09:31:12Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-111109"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pfefferle/wordpress-webmention/pull/698"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/class-receiver.php#L267"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/class-receiver.php#L453"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/entity/class-item.php#L125"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/entity/class-item.php#L297"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.1/includes/handler/class-meta.php#L78"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/webmention/tags/5.10.2/includes/class-receiver.php"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/0b283d17-b89f-467d-8a79-cdf7b9bfdb65?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}



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