Vulnerability Description
Concrete CMS before 9.5.3 improperly neutralized a user-supplied custom date format when rendering conversation messages, resulting in reflected cross-site scripting. An attacker could execute arbitrary JavaScript in the browser of a user who was tricked into submitting a crafted POST request to the conversation view endpoint. Exploitation was aided by the absence of a CSRF token on the endpoint, which allowed the payload to be delivered through an auto-submitting cross-origin POST without authentication. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-81925?
CVE-2026-81925 is a documented vulnerability. Concrete CMS before 9.5.3 improperly neutralized a user-supplied custom date format when rendering conversation messages, resulting in reflected cross-site scripting. An attacker could execute arbitra...
How severe is CVE-2026-81925?
CVSS scoring is not yet available for CVE-2026-81925. Check NVD for updates.
Is there a patch for CVE-2026-81925?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.