CVE-2026-76834

High

Description

b2evolution CMS versions 6.7.8 through 7.2.5 contain an incomplete fix for CVE-2016-8901 where the serialized-array object check in param_check_serialized_array() fails to reject payloads with negative integer array keys. Unauthenticated attackers can submit crafted serialized PHP objects via POST requests to htsrv/call_plugin.php that bypass validation and reach unserialize(), instantiating arbitrary PHP objects with attacker-chosen properties that may enable code execution if suitable POP gadget chains exist.

SeverityHigh

CVSS8.1

Exploit probability—

Productb2evolution CMS

PublishedSep 17, 2026

First seenSep 17, 2026

Weakness typeCWE-502Deserialization of untrusted data

How to fix

Patches

Vendor advisories

b2evolution.net/news/2022/03/26/2022-update-eol

Affected products

Product	Affected versions	Fixed in
b2evolution b2evolution CMS	6.7.8 ≤ v ≤ 7.2.5	—

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