CVE-2026-8365 json
Blocksy <= 2.1.41 - Authenticated (Contributor+) PHP Object Injection via Deserialization of Untrusted Data via 'blocksy_meta' REST API Field
published 2026-06-09 5 mo ago modified 2026-07-23 3 mo ago also EUVD-2026-35379
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 66%
- public exploits
- 0
- none known
Summary
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().
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 5 mo ago
Exploit prediction
1.12% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- creativethemeshq Blocksy
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/fd216743-ce8d-4632-9fd1-d63502c2dfcd?source=cve
- themes.trac.wordpress.org /browser/blocksy/trunk/inc/classes/db-versioning/utils/db-search-replacer.php#L98
- themes.trac.wordpress.org /browser/blocksy/2.1.41/inc/classes/db-versioning/utils/db-search-replacer.php#L98
- themes.trac.wordpress.org /browser/blocksy/trunk/admin/helpers/meta-boxes.php#L104
- themes.trac.wordpress.org /browser/blocksy/2.1.41/admin/helpers/meta-boxes.php#L104
- themes.trac.wordpress.org /browser/blocksy/trunk/admin/helpers/validator.php#L75
- themes.trac.wordpress.org /browser/blocksy/2.1.41/admin/helpers/validator.php#L75
- themes.trac.wordpress.org /browser/blocksy/trunk/inc/classes/raii.php#L12
- themes.trac.wordpress.org /browser/blocksy/2.1.41/inc/classes/raii.php#L12
- themes.trac.wordpress.org /browser/blocksy/2.1.35/inc/classes/db-versioning/utils/db-search-replacer.php#L98
- themes.trac.wordpress.org /browser/blocksy/2.1.35/admin/helpers/meta-boxes.php#L104
- themes.trac.wordpress.org /browser/blocksy/2.1.35/admin/helpers/validator.php#L75
- themes.trac.wordpress.org /browser/blocksy/2.1.35/inc/classes/raii.php#L12
Sources
- CVE List CVE-2026-8365
- NVD CVE-2026-8365
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.