CVE-2026-76834
- Published17 Sept 2026
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.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HRemediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
References
- https://b2evolution.net/news/2022/03/26/2022-update-eol
- https://gist.github.com/axg11/3e29501c33f6e1e05ac2a00107afd64e
- https://github.com/b2evolution/b2evolution
- https://github.com/b2evolution/b2evolution/blob/7.2.5/htsrv/call_plugin.php#L49
- https://github.com/b2evolution/b2evolution/blob/7.2.5/inc/_core/_param.funcs.php#L2860
- https://github.com/b2evolution/b2evolution/commit/25c21cf9cc4261324001f9039509710b37ee2c4d
- https://github.com/b2evolution/b2evolution/commit/335abf09bcea61717bd00bc1e3889f8100ebd1bb
- https://github.com/b2evolution/b2evolution/commit/999b5ad1d59760d7e450ceb541f55432fc74cd27
- https://www.vulncheck.com/advisories/b2evolution-cms-6.7.8-through-7.2.5-object-injection-via-negative-integer-array-key
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-76834 being actively exploited?
CVE-2026-76834 is not in the CISA KEV catalog.
How severe is CVE-2026-76834?
CVE-2026-76834 has a CVSS 3.1 base score of 8.1, rated high.
How do I fix CVE-2026-76834?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-76834 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.