CVE-2026-81820Network attack vectorHinoki check available

Authenticated timeline manipulation via crafted MISP fields

Published Aug 27, 2026 · Updated Aug 27, 2026

HTML injection in Flowintel 3.3.0 and earlier allows remote authenticated users to alter case-history timelines via crafted MISP fields. The renderer concatenates object identifiers, names, attributes, comments, timestamps, and IDS flags into HTML; DOMPurify blocks XSS vectors but permits other elements, including forms. A user able to supply MISP object data can persist deceptive interface content that another authenticated user sees when viewing the timeline.

CVSS severity5.1
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

HTML injection in Flowintel 3.3.0 and earlier allows remote authenticated users to alter case-history timelines via crafted MISP fields. The renderer concatenates object identifiers, names, attributes, comments, timestamps, and IDS flags into HTML; DOMPurify blocks XSS vectors but permits other elements, including forms. A user able to supply MISP object data can persist deceptive interface content that another authenticated user sees when viewing the timeline.

The record

CVE
CVE-2026-81820
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
Computer Incident Response Center Luxembourg (CIRCL)
Product
Flowintel
Classifications
CWE-79, T1565.002
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=3.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Computer Incident Response Center Luxembourg (CIRCL) · Flowintelversion=0 <=3.3.0

Published CVSS scores

5.1CIRCLCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1565.002Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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