← Vulnerability feed

Vulnerability record · CVE-2026-3452 · published 4 March 2026

CVE-2026-3452: Concretecms concrete cms deserialization of untrusted data vulnerability

Concretecms · Concrete Cms

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.

8.9 CVSS 4.0 High EPSS 0.85% · top 43.4% CWE-502 · Deserialization of untrusted data
8.9CVSS 4.0 base score
0.85%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

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.

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:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes PatchRelease NotesVendor Advisory
https://github.com/concretecms/concretecms/pull/12826/changes/167f16e4805d8ab546d2997c753ac21bf4854920:// Broken Link

Track CVE-2026-3452 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-48648Concretecms concrete cms incorrect default permissions vulnerabilityConcrete CMS before 8.5.13 and 9.x before 9.2.2 allows unauthorized access because directories can be created with insecure permissions. File creatio…EPSS 1.2%9.8CVE-2022-21829Concretecms concrete cms cleartext transmission vulnerabilityConcrete CMS Versions 9.0.0 through 9.0.2 and 8.5.7 and below can download zip files over HTTP and execute code from those zip files which could lead…EPSS 1.8%9.8CVE-2021-22958Concretecms concrete cms server-side request forgery (ssrf) vulnerabilityA Server-Side Request Forgery vulnerability was found in concrete5 < 8.5.5 that allowed a decimal notation encoded IP address to bypass the limitatio…EPSS 1.2%9.8CVE-2021-40098Concretecms concrete cms path traversal vulnerabilityAn issue was discovered in Concrete CMS through 8.5.5. Path Traversal leading to RCE via external form by adding a regular expression.EPSS 1.6%9.4CVE-2026-8134Concretecms concrete cms relative path traversal vulnerabilityConcrete CMS 9.5.0 and below fails to sanitize path traversal sequences in the ptComposerFormLayoutSetControlCustomTemplate field when saving page ty…EPSS 1.1%9.1CVE-2022-30117Concretecms concrete cms path traversal vulnerabilityConcrete 8.5.7 and below as well as Concrete 9.0 through 9.0.2 allow traversal in /index.php/ccm/system/file/upload which could result in an Arbitrar…EPSS 2.1%9.1CVE-2021-40102Concretecms concrete cms deserialization of untrusted data vulnerabilityAn issue was discovered in Concrete CMS through 8.5.5. Arbitrary File deletion can occur via PHAR deserialization in is_dir (PHP Object Injection ass…EPSS 1.3%8.9CVE-2026-8135Concretecms concrete cms deserialization of untrusted data vulnerabilityConcrete CMS 9.5.0 and below is vulnerable to Remote Code Execution due to insecure deserialization occurring in the ExpressEntryList block controlle…EPSS 0.74%

Source: NIST National Vulnerability Database (record CVE-2026-3452), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.