{"id":"CVE-2026-19902","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-19902","generatedAt":"2026-10-28T01:39:26.870Z","title":"The Ad Inserter – Ad Manager & AdSense Ads plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the Referer header in all versions up to, and including, 2.8.18 due to insufficient input sanitization and output escaping on the…","description":"The Ad Inserter – Ad Manager & AdSense Ads plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the Referer header in all versions up to, and including, 2.8.18 due to insufficient input sanitization and output escaping on the '{search-query}' dynamic tag. When an ad block's code contains that tag, replace_ai_tags() reads $_SERVER['HTTP_REFERER'] and tests it with the regex /[\\.\\/](google|yahoo|bing|ask)\\.[a-z\\.]{2,5}[\\/]/i. The leading [\\.\\/] class matches a literal slash, so any referrer merely containing a segment such as '/google.com/' passes as a search-engine referral; the plugin then percent-decodes the referring query with parse_str() and substitutes the resulting 'q' (or 'p') value into the block via preg_replace() with no escaping. This makes it possible for unauthenticated attackers to execute arbitrary JavaScript in the context of the site for any visitor, including a signed-in administrator, by luring them to an attacker-controlled page that frames or links to any ordinary post. Exploitation requires the site to have an ad block whose code uses the '{search-query}' tag with automatic insertion enabled — a documented plugin feature used as intended.","published":"2026-10-01T08:16:52.000Z","lastModified":"2026-10-03T16:16:37.000Z","status":"Deferred","sourceIdentifier":"security@wordfence.com","cvss":{"version":"3.1","score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"cwe":["CWE-79"],"affected":[],"epss":{"score":0.00259,"percentile":0.17493,"date":"2026-10-26","history":[{"date":"2026-10-02","score":0.00259,"percentile":0.16019}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.26%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-01T08:16:52.000Z","detail":{"score":"6.1","severity":"MEDIUM","publishedAt":"2026-10-01T08:16:51.580Z"},"summary":"New CVE, medium severity (CVSS 6.1)."}],"references":[{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13018","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13022","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13025","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13093","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/class.php#L3297","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/changeset/3709957/ad-inserter/trunk/ad-inserter.php","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/changeset?reponame=&new=3709970%40ad-inserter%2Ftags%2F2.8.19&old=3624916%40ad-inserter%2Ftags%2F2.8.18","source":"security@wordfence.com"},{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/5d632cce-40a9-4969-b213-8370ae75287e?source=cve","source":"security@wordfence.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-19902","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}