SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-81820

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.

MEDIUM 5.1EPSS 0.25%

Does this matter?

Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.

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 4.0
5.1 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.25% probability · 17th percentile
CISA KEV
Not listed
Weakness
CWE-79
Source
5a6e4751-2f3f-4070-9419-94fb35b644e8

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.