Vulnerability details
CVE-2026-8203
Concrete CMS Concrete CMS
Concrete CMS 9.5.0 and below has Stored XSS on the height parameter
CVSS 4.0
7.3High
Official description
Concrete CMS 9.5.0 and below has Stored XSS on the height parameter. The controller does not validate or sanitize $height. Any user with editor privileges can inject malicious JavaScript that executes in the context of any visitor's browser, potentially leading to session hijacking, credential theft, or other malicious actions. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Alfin Joseph for reporting.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.3High | 4.0 | CVEProject cvelistV5 (CNA) (ConcreteCMS) | CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Concrete CMS | Concrete CMS | 5 ≤ v ≤ 9.5.0 | CVEProject cvelistV5 (CNA) |
References and advisories
1
Kolun on Telegram @kolunsec
Exploited CVEs, key news and a daily digest
Alerts for this product's next CVEsFollow the product to get new vulnerabilities on Telegram.
Details
- Published
- 2026-05-22
- Last updated
- 2026-05-22
- State
- Published
- Assigner (CNA)
- ConcreteCMS
Exploit prediction (EPSS)
0.12%
Probability of exploitation in 30 days
1.9%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-79Improper neutralization of input during web page generation ('cross-site scripting')