b2evolution CMS 6.7.8 through 7.2.5 Object Injection via Negative Integer Array Key
Summary
| CVE | CVE-2026-76834 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-17 16:17:42 UTC |
| Updated | 2026-09-18 18:17:13 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 9.2 CRITICAL from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.008470000 probability, percentile 0.565060000 (date 2026-09-20)
Problem Types: CWE-502 | CWE-502 Deserialization of Untrusted Data
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.2 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 9.2 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Secondary | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | B2evolution | B2evolution CMS | affected 6.7.8 7.2.5 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/b2evolution/b2evolution | [email protected] | github.com | |
| github.com/b2evolution/b2evolution/blob/7.2.5/htsrv/call_plugin.php | [email protected] | github.com | |
| b2evolution.net/news/2022/03/26/2022-update-eol | [email protected] | b2evolution.net | |
| github.com/b2evolution/b2evolution/commit/25c21cf9cc4261324001f903950971... | [email protected] | github.com | |
| github.com/b2evolution/b2evolution/commit/999b5ad1d59760d7e450ceb541f554... | [email protected] | github.com | |
| github.com/b2evolution/b2evolution/blob/7.2.5/inc/_core/_param.funcs.php | [email protected] | github.com | |
| github.com/b2evolution/b2evolution/commit/335abf09bcea61717bd00bc1e3889f... | [email protected] | github.com | |
| www.vulncheck.com/advisories/b2evolution-cms-6.7.8-through-7.2.5-object-injecti... | [email protected] | www.vulncheck.com | |
| gist.github.com/axg11/3e29501c33f6e1e05ac2a00107afd64e | [email protected] | gist.github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Adrian Gaitan (en)
CNA: VulnCheck (en)
There are currently no legacy QID mappings associated with this CVE.