CVE-2026-18119
Concrete CMS below 9.5.3 is vulnerable to Stored XSS via unsanitized inline block custom style values
- State
- Published
- Severity
- 7.0 High
- Published
- Sep 14, 2026
- Updated
- Sep 14, 2026
- Reserved
- Jul 28, 2026
Description
Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before writing them into page CSS via a DOM sink, permitting stored cross-site scripting. An editor-level user could execute script in an administrator's session and escalate privileges. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.0 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Nguyen Manh Thuan for reporting.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.0 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N | ConcreteCMS |
Weaknesses
- CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')
Affected Products
| Product | Versions |
|---|---|
Concrete CMSConcrete CMS |
|
References
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.