---
id: CVE-2026-76834
title: >-
  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
summary: >-
  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…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: b2evolution
product: b2evolution CMS
affected:
  - cms >= 6.7.8 <= 7.2.5
published: '2026-09-17'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T17:17:47.930'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76834'
references:
  - url: 'https://b2evolution.net/news/2022/03/26/2022-update-eol'
    label: disclosure@vulncheck.com
  - url: 'https://gist.github.com/axg11/3e29501c33f6e1e05ac2a00107afd64e'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/b2evolution/b2evolution'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/b2evolution/b2evolution/blob/7.2.5/htsrv/call_plugin.php#L49
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/b2evolution/b2evolution/blob/7.2.5/inc/_core/_param.funcs.php#L2860
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/b2evolution/b2evolution/commit/25c21cf9cc4261324001f9039509710b37ee2c4d
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/b2evolution/b2evolution/commit/335abf09bcea61717bd00bc1e3889f8100ebd1bb
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/b2evolution/b2evolution/commit/999b5ad1d59760d7e450ceb541f55432fc74cd27
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/b2evolution-cms-6.7.8-through-7.2.5-object-injection-via-negative-integer-array-key
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.00847
epssPercentile: 0.56567
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-18T18:04:36.961014Z'
ingestedAt: '2026-09-17T16:21:47.710Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.