Vulnerability · Published Aug 27, 2026 · Assigned by CIRCL
CVE-2026-81820Flowintel HTML Injection in MISP Case History Timeline via Crafted Object Attributes
Medium 5.1
In plain English
A medium-severity cross-site scripting in flowintel from flowintel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).
Official description
Affected versions of Flowintel construct timeline HTML using attacker-controllable MISP object fields such as: * object UUID; * object name; * attribute value; * attribute type; * comment; * first/last seen values; * IDS flag. Those values were concatenated directly into HTML strings before rendering. The upstream commit explicitly states that DOMPurify removed XSS vectors but still allowed other HTML elements, such as forms, through. The fix replaces direct string interpolation with DOM construction via document.createElement() and assigns all attacker-controlled values using textContent. The headline is similarly converted to escaped HTML through a temporary element. Version impacted =>3.3.0
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N