{"id":"CVE-2026-8365","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-8365","generatedAt":"2026-10-28T02:22:49.763Z","title":"The Blocksy theme for WordPress is vulnerable to PHP Object Injection leading to Remote Code Execution via the 'blocksy_meta' REST API field and the V200 database migration in versions up to and including 2.1.35.","description":"The Blocksy theme for WordPress is vulnerable to PHP Object Injection leading to Remote Code Execution via the 'blocksy_meta' REST API field and the V200 database migration in versions up to and including 2.1.35. This is due to insufficient input sanitization in the blocksy_sanitize_post_meta_options() function, which only blocks values containing '<' or '>' and does not prevent serialized PHP object strings from being stored in post meta, combined with the SearchReplacer::run_recursively() function unconditionally deserializing all string values via @unserialize() during migration without restricting allowed classes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a serialized Blocksy\\RaiiPattern object into post meta that, when the V200 migration runs on an upgraded site, is deserialized and triggers RaiiPattern::__destruct(), which executes arbitrary PHP callables via call_user_func().","published":"2026-06-09T09:16:31.000Z","lastModified":"2026-07-23T08:10:00.000Z","status":"Deferred","sourceIdentifier":"security@wordfence.com","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-502"],"affected":[],"epss":{"score":0.01121,"percentile":0.65973,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/meta-boxes.php#L104","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/validator.php#L75","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/db-versioning/utils/db-search-replacer.php#L98","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/raii.php#L12","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/meta-boxes.php#L104","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/validator.php#L75","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/2.1.41/inc/classes/db-versioning/utils/db-search-replacer.php#L98","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/2.1.41/inc/classes/raii.php#L12","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/trunk/admin/helpers/meta-boxes.php#L104","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/trunk/admin/helpers/validator.php#L75","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/trunk/inc/classes/db-versioning/utils/db-search-replacer.php#L98","source":"security@wordfence.com"},{"url":"https://themes.trac.wordpress.org/browser/blocksy/trunk/inc/classes/raii.php#L12","source":"security@wordfence.com"},{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/fd216743-ce8d-4632-9fd1-d63502c2dfcd?source=cve","source":"security@wordfence.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-8365","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."}