Blocksy <= 2.1.41 - Authenticated (Contributor+) PHP Object Injection via Deserialization of Untrusted Data via 'blocksy_meta' REST API Field
| CVE | CVE-2026-8365 |
|---|---|
| CVSS | 8.8 (High) |
| Publicly Published | June 8, 2026 |
| Last Updated | June 9, 2026 |
| Researcher |
Quốc Huy (jtwings)
- Puramu
|
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().
References
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
- themes.trac.wordpress.org
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Vulnerability Details for Blocksy
| Software Type | Theme |
|---|---|
| Software Slug | blocksy (view on wordpress.org) |
| Patched? | Yes |
| Remediation | Update to version 2.1.42, or a newer patched version |
| Affected Version |
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| Patched Version |
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Recent vulnerabilities in Blocksy
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