CVE-2026-81820

Technical 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

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References