CVE-2026-81814Network attack vector

Stored XSS via unsafe calendar title rendering

Published Aug 27, 2026 · Updated Aug 27, 2026

Stored XSS in CIRCL Flowintel 3.3.0 and earlier allows remote authenticated users to execute script via a crafted case title. The calendar event renderer assigns the case-derived title to titleEl.innerHTML, causing the browser to interpret stored markup instead of text. Case-title write access is required, and execution occurs when another authenticated user opens a calendar containing the event, exposing data and actions available to that user's session.

CVSS severity5.1
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in CIRCL Flowintel 3.3.0 and earlier allows remote authenticated users to execute script via a crafted case title. The calendar event renderer assigns the case-derived title to titleEl.innerHTML, causing the browser to interpret stored markup instead of text. Case-title write access is required, and execution occurs when another authenticated user opens a calendar containing the event, exposing data and actions available to that user's session.

The record

CVE
CVE-2026-81814
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
Computer Incident Response Center Luxembourg (CIRCL)
Product
Flowintel
Classifications
CWE-79, T1059.007
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:L/VI:L/VA:N/SC:L/SI:L/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')
T1059.007JavaScript/JScript

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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