{"cve":"CVE-2026-8365","nvd":{"published":"2026-06-09T09:16:31.013","modified":"2026-07-23T08:10:00.137","status":"Deferred","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().","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-502"],"references":["https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/meta-boxes.php#L104","https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/validator.php#L75","https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/db-versioning/utils/db-search-replacer.php#L98","https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/raii.php#L12","https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/meta-boxes.php#L104"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:38:48.522727527+00:00"},"epss":{"cve":"CVE-2026-8365","score":0.01121,"percentile":0.66209,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}