CVE-2026-81820

Flowintel HTML Injection in MISP Case History Timeline via Crafted Object Attributes

Published Aug 27, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
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

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Flowintel
Flowintel flowintel
Vendors & Products Flowintel
Flowintel flowintel
Type Values Removed Values Added
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
Title Flowintel HTML Injection in MISP Case History Timeline via Crafted Object Attributes
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 5.1, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
CIRCL
Published
Updated
Aug 27, 2026, 7:39 PM
Reserved
Aug 27, 2026, 1:25 PM
Status
Deferred
Published
Aug 27, 2026, 5:21 PM
Modified
Aug 28, 2026, 3:28 PM