Vulnerability Description
Concrete CMS below 9.5.3 does not apply HTML output escaping to the file description and tags fields when rendering the Document Library block, so a user with permission to edit file properties could store a script payload that executed in the browser of any visitor to a page displaying the block with the description or tags column enabled, including unauthenticated visitors. Successful exploitation could allow theft of session data or actions performed in the visitor's context. The block controller returned the description and tags values without the h() escaping already applied to the title column, and the block view template wrote the returned value directly into the results table The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N. Thanks Nguyen Manh Thuan for reporting.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Concretecms | Concrete Cms | < 9.5.3 |
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-81917?
CVE-2026-81917 is a vulnerability with a CVSS score of 5.4 (MEDIUM). Concrete CMS below 9.5.3 does not apply HTML output escaping to the file description and tags fields when rendering the Document Library block, so a user with permission to edit file properties could ...
How severe is CVE-2026-81917?
CVE-2026-81917 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-81917?
Check the references section above for vendor advisories and patch information. Affected products include: Concretecms Concrete Cms.