CVE-2026-8365

Blocksy <= 2.1.41 - Authenticated (Contributor+) PHP Object Injection via Deserialization of Untrusted Data via 'blocksy_meta' REST API Field

HIGH
8.8
CVSS Score
Published: June 9, 2026 at 08:29 AM UTC
Updated: July 23, 2026 at 07:32 PM UTC
1 product affected across 1 vendorBlocksy

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Severity
HIGH8.8
Exploit prediction
EPSS 1%
SSVC
No known exploit

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().

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

60%
v ≤ 2.1.41

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHWordfence
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-502

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