{"id":"CVE-2026-19902","state":"PUBLISHED","title":"Ad Inserter <= 2.8.18 - Reflected Cross-Site Scripting via {search-query} Dynamic Tag (Referer Header)","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.","publishedAt":"2026-10-01T07:40:23.197Z","updatedAt":"2026-10-03T15:42:52.231Z","severity":{"score":6.1,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","source":"Wordfence"},"assigner":"Wordfence","products":["spacetime Ad Inserter – Ad Manager & AdSense Ads"],"affected":[{"vendor":"spacetime","product":"Ad Inserter – Ad Manager & AdSense Ads","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.8.18","versionType":"semver"}]}],"references":["https://www.wordfence.com/threat-intel/vulnerabilities/id/5d632cce-40a9-4969-b213-8370ae75287e?source=cve","https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13093","https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13018","https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13022","https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13025","https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/class.php#L3297","https://plugins.trac.wordpress.org/changeset?reponame=&new=3709970%40ad-inserter%2Ftags%2F2.8.19&old=3624916%40ad-inserter%2Ftags%2F2.8.18","https://plugins.trac.wordpress.org/changeset/3709957/ad-inserter/trunk/ad-inserter.php"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/19xxx/CVE-2026-19902.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-19902","state":"PUBLISHED","datePublished":"2026-10-01T07:40:23.197Z","dateUpdated":"2026-10-03T15:42:52.231Z","assignerShortName":"Wordfence","assignerOrgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateReserved":"2026-08-14T19:15:32.388Z"},"containers":{"cna":{"title":"Ad Inserter <= 2.8.18 - Reflected Cross-Site Scripting via {search-query} Dynamic Tag (Referer Header)","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"spacetime","product":"Ad Inserter – Ad Manager & AdSense Ads","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.8.18","versionType":"semver"}]}],"references":[{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/5d632cce-40a9-4969-b213-8370ae75287e?source=cve"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13093"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13018"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13022"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/ad-inserter.php#L13025"},{"url":"https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.18/class.php#L3297"},{"url":"https://plugins.trac.wordpress.org/changeset?reponame=&new=3709970%40ad-inserter%2Ftags%2F2.8.19&old=3624916%40ad-inserter%2Ftags%2F2.8.18"},{"url":"https://plugins.trac.wordpress.org/changeset/3709957/ad-inserter/trunk/ad-inserter.php"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","baseScore":6.1,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"Wordfence","orgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateUpdated":"2026-10-01T07:40:23.197Z"},"credits":[{"lang":"en","type":"finder","value":"Yuto Hyakumoto"}],"timeline":[{"time":"2026-08-14T19:31:26.000Z","lang":"en","value":"Vendor Notified"},{"time":"2026-09-30T19:33:23.000Z","lang":"en","value":"Disclosed"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-19902","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-03T15:35:45.406125Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-03T15:42:52.231Z"}}]}}}