Medium

Concrete CMS has a stored Cross-site Scripting (XSS) vulnerability

  • Disclosed: 04.03.2026
  • Updated: 11.10.2026 10:22

In Concrete CMS below version 9.4.8, A stored Cross-site Scripting (XSS) vulnerability exists in the search block where page names and content are rendered without proper HTML encoding in search results. This allows authenticated, rogue administrators to inject malicious JavaScript through page names that executes when users search for and view those pages in search results. 

The Concrete CMS security team thanks zolpak for reporting.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package concrete5/concrete5 < 9.4.8 9.4.8

References

CVSS score -
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-79
Platform
Composer
Package
concrete5/concrete5
Disclosed
04.03.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-mm5f-5rqw-574f - CC BY 4.0

Vulnerability history: concrete5/concrete5

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (121) in the archive
Total entries
121
First → latest
10.2021 06.2026
Without a fix
10
Exploited in attacks
0

Severity breakdown

  • Critical 2
  • High 16
  • Medium 65
  • Low 38

Disclosures per year

  1. 2021: 2
  2. 2022: 18
  3. 2023: 21
  4. 2024: 21
  5. 2025: 5
  6. 2026: 54
Severity:
  1. High CVE-2026-8421 < 9.5.1 9.5.1
  2. Critical · 7.2 CVE-2026-8134 < 9.5.1 9.5.1
  3. Concrete CMS has a stored Cross-site Scripting (XSS) vulnerability this entry
    Medium CVE-2026-3244 < 9.4.8 9.4.8
  4. High · 8.8 CVE-2022-43693 < 8.5.10, >= 9.0.0RC1, < 9.1.3 8.5.10, 9.1.3
  5. High CVE-2021-22954 < 9.0.0 9.0.0
  6. High · 7.2 CVE-2020-11476 < 8.5.3 8.5.3
  7. High · 8.2 CVE-2021-22958 < 8.5.5 8.5.5

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