XSS in Concrete Cms
CVE-2026-3242
In Concrete CMS below version 9.4.8, a rogue administrator can add stored XSS via the Switch Language block. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with 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. Thanks M3dium for reporting.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (17.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 17.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Concrete Cms — versions 5
- Concretecms Concrete Cms
Weakness classification (CWE)
References
- ff5b8ace-8b95-4078-9743-eac1ca5451de (Exploit, Issue Tracking, Vendor Advisory)
- ff5b8ace-8b95-4078-9743-eac1ca5451de (Patch, Release Notes, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-3242?
- CVE-2026-3242 is a medium-severity vulnerability in Concrete Cms, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-03-04.
- How severe is CVE-2026-3242?
- Medium severity. CVSS v3 base score is 4.8 out of 10.