Flowintel up to 3.3.0 Timeline HTML Construction HTML injection

Summaryinfo

A vulnerability identified as problematic has been detected in Flowintel up to 3.3.0. The impacted element is an unknown function of the component Timeline HTML Construction. The manipulation leads to HTML injection. This vulnerability is listed as CVE-2026-81820. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Flowintel up to 3.3.0 and classified as problematic. This issue affects some unknown functionality of the component Timeline HTML Construction. The manipulation with an unknown input leads to a html injection vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. The summary by CVE is:

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

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-81820 since 08/27/2026. The exploitation is known to be easy. The attack may be initiated remotely. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Name

• Flowintel

Version

• 3.0
• 3.1
• 3.2
• 3.3.0

Website

• Product: https://github.com/flowintel/flowintel/

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