CVE-2026-81753

Flowintel Stored XSS in Case Notes via Malicious Mermaid Diagram Content

Published Aug 27, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
Description
Affected versions of Flowintel render Mermaid blocks contained in stored case notes without sufficiently neutralizing attacker-controlled markup. Because Mermaid note content is persisted and later rendered for other users, an attacker with permission to create or edit a note could store a crafted Mermaid payload that results in JavaScript execution when another user views the affected case note.

The patch adds explicit Mermaid detection and HTML escaping around the token content before the generated Mermaid wrapper is returned. It also moves the wrapping logic earlier in page initialization so Markdown instances are protected consistently.

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 render Mermaid blocks contained in stored case notes without sufficiently neutralizing attacker-controlled markup. Because Mermaid note content is persisted and later rendered for other users, an attacker with permission to create or edit a note could store a crafted Mermaid payload that results in JavaScript execution when another user views the affected case note. The patch adds explicit Mermaid detection and HTML escaping around the token content before the generated Mermaid wrapper is returned. It also moves the wrapping logic earlier in page initialization so Markdown instances are protected consistently. Version impacted >= 3.3.0
Title Flowintel Stored XSS in Case Notes via Malicious Mermaid Diagram Content
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:L/VI:L/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
CIRCL
Published
Updated
Aug 27, 2026, 3:54 PM
Reserved
Aug 27, 2026, 12:06 PM
Status
Deferred
Published
Aug 27, 2026, 1:18 PM
Modified
Aug 28, 2026, 3:28 PM