CVE-2026-81820
Received
Received - Intake
Stored XSS in Flowintel Timeline via MISP Object Fields
Vulnerability report for CVE-2026-81820, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-27
Last updated on: 2026-08-27
Assigner: CIRCL
Description
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
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| flowintel | flowintel | 3.3.0 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| 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. |
