Concrete CMS below 9.4.8 is vulnerable to stored deserialization leading to RCE in the Express Entry List block.
Published Mar 4, 2026
8.9
HIGHCVSS 4.0
EPSS 0.95%
Description
Concrete CMS below version 9.4.8 is vulnerable to Remote Code Execution by stored PHP object injection into the Express Entry List block via the columns parameter. An authenticated administrator can store attacker-controlled serialized data in block configuration fields that are later passed to unserialize() without class restrictions or integrity checks. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 8.9 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H. Thanks YJK ( @YJK0805 https://hackerone.com/yjk0805 ) of ZUSO ART https://zuso.ai/ for reporting.
Affected products
-
- Version 5StatusaffectedConstraints<9.4.8
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Concrete CMS | Concrete CMS | unaffected |
|
- < 9.4.8
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
TotalDecision
n/aAssessed Mar 4, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
Mar–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 0.95% (0.00949) | 59.87th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.60% (0.00605) | 44.11th | v5 (v2026.06.15) |
| Mar 4, 2026 | 0.40% (0.00402) | 60.35th | v4 (v2025.03.14) |
References (5)
- https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes PatchRelease NotesVendor Advisory
- https://github.com/advisories/GHSA-gj26-w59c-29mf Advisory
- https://github.com/concretecms/concretecms/pull/12826/changes/167f16e4805d8ab546d2997c753ac21bf4854920
- https://github.com/concretecms/concretecms/pull/12826/changes/167f16e4805d8ab546d2997c753ac21bf4854920:// Broken Link
- https://nvd.nist.gov/vuln/detail/CVE-2026-3452
Change history (0)
No recorded changes yet.