CVE-2026-76834b2evolution CMS 6.7.8 through 7.2.5 Object Injection via Negative Integer Array Key
- 9.2CriticalCVSS base score
- 0.85%Exploitation in 30 daysEPSS · top 41% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By VulnCheck
- 29 days later
· 29 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | Critical9.2 | 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 |
| VulnCheckCNA (assigner) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Deferred | 4.0 | Critical9.2 | 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 (exploitation in 30 days)
- 0.85% · top 41% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.2.
Affected products
- affected 6.7.8 – ≤ 7.2.5
References
References9
- https://gist.github.com/axg11/3e29501c33f6e1e05ac2a00107afd64e (opens in a new tab)technical-description
- https://github.com/b2evolution/b2evolution/blob/7.2.5/inc/_core/_param.funcs.php#L2860 (opens in a new tab)technical-description
- https://github.com/b2evolution/b2evolution/blob/7.2.5/htsrv/call_plugin.php#L49 (opens in a new tab)technical-description
- Incomplete fix for CVE-2016-8901 (1 of 2) (opens in a new tab)patch
- Incomplete fix for CVE-2016-8901 (2 of 2) (opens in a new tab)patch
- Introduces the flawed regular expression, first released in 6.7.8 (opens in a new tab)technical-descriptionpatch
- b2evolution CMS end-of-life announcement (opens in a new tab)vendor-advisory
- https://github.com/b2evolution/b2evolution (opens in a new tab)product
- VulnCheck Advisory: b2evolution CMS 6.7.8 through 7.2.5 Object Injection via Negative Integer Array Key (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-81681 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-76834)Record last updated .