Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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ReconAuthenticate to Flowintel with low-privileged analyst account
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DeliveryCreate or edit case note embedding crafted Mermaid block with JavaScript payload
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ExploitNote persisted in application database
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InstallHigher-privileged user views case note in browser
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C2Mermaid block renders without HTML escaping
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ExecuteInjected JavaScript executes in victim's session
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ImpactExfiltrate session token or perform authenticated actions
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires an attacker to hold an authenticated Flowintel session with permission to create or edit case notes - unauthenticated access is insufficient. The target must be running Flowintel version 3.3.0 or later. A second user (the victim) must view the malicious note in a browser; exploitation does not occur server-side or via automated scanning. The limiting factors are the authenticated prerequisite (PR:L per CVSS), the requirement for victim page load (UI:P), and the niche deployment context of the product. Default installations without custom role restrictions may grant note-edit rights broadly to all analysts, which widens the attacker pool within an organization. |
| Impact | Real-world risk is moderate and context-dependent. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:P) confirms network reachability with low complexity but meaningfully constrains exploitation to authenticated users with note-creation rights and requires a victim to passively load the malicious note. Impact metrics (VC:L/VI:L and SC:L/SI:L) reflect typical stored-XSS consequences: session token theft, forced browser actions, or defacement within the application. No EPSS data is available in the provided intelligence; however, the combination of no KEV listing, no identified POC, and the niche deployment footprint of Flowintel collectively indicate this is not a widespread opportunistic threat. The primary realistic risk is insider or compromised-account abuse in threat intelligence teams where analysts share case notes with elevated-privilege colleagues. CVSS signals are internally consistent with the description - no contradictions to flag. |
| Exploit ScenarioDerived | An analyst account with case-note editing rights crafts a Mermaid-fenced code block embedding a JavaScript payload and saves it to a shared case note. When a higher-privileged colleague - such as a case manager or administrator - opens the note in their browser, the unescaped Mermaid content renders and the injected script executes under the victim's session, potentially exfiltrating their session token to an attacker-controlled endpoint or performing authenticated API actions on their behalf. No public proof-of-concept has been identified, but the technique is standard stored-XSS and requires no specialized tooling beyond a browser. |
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Alert meAnalysisAIv1 – Aug 27, 2026
Stored cross-site scripting in Flowintel case notes allows an authenticated low-privileged user to inject malicious JavaScript via crafted Mermaid diagram blocks, which executes in the browser of any user who subsequently views the affected note. Affected are Flowintel deployments running version 3.3.0 and later; the CVSS 4.0 score of 5.1 reflects that exploitation requires both an authenticated session with note-edit rights and passive victim interaction. No public exploit code has been identified and this vulnerability is not listed in the CISA KEV catalog at time of analysis.
RemediationAI
The primary fix is to apply or pull the upstream patch commit 61c97e67f5d04030f26e7900c470b52f9f37da06 from the Flowintel GitHub repository (https://github.com/flowintel/flowintel/commit/61c97e67f5d04030f26e7900c470b52f9f37da06); operators running from source should rebase or cherry-pick this commit. A tagged patched release version is not independently confirmed from the available data, so verify with the upstream maintainers before assuming any specific version tag is safe. As a compensating control while patching, restrict the note-creation and note-editing permissions to only the minimum required set of trusted users, reducing the pool of potential injectors. Content Security Policy headers that block inline script execution could also limit XSS impact if configurable at the deployment layer, though they do not eliminate the underlying flaw.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Flowintel is an open-source threat intelligence case management platform developed in the CIRCL ecosystem (CPE: cpe:2.3:a:flowintel:flowintel:*:*:*:*:*:*:*:*). Its Markdown renderer supports Mermaid.js fence blocks for diagramming. The root cause (CWE-79: Improper Neutralization of Input During Web Page Generation) lies in the Mermaid rendering path within base.html: the template detected Mermaid-fenced code tokens and wrapped their content in a pre or div with a mermaid class, but used raw token content rather than the already-available HTML-escaped variable. The fix introduces _hasMermaidInfo() and _matchMermaidWrapper() helper functions that tighten Mermaid block detection, switch to the escaped variable for all Mermaid content, and relocate the Vue/sidebar initialization block to earlier in page load so Markdown processing is consistently protected across all template inheritance scenarios.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
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
Stored XSS requires authenticated note creation (PR:L) and victim page view (UI:R); JavaScript executes in victim's browser context changing scope (S:C), with low C/I impact typical of session-theft XSS.
Primary rating from Vendor (CIRCL).
CVSS VectorVendor: CIRCL
DescriptionCVE.org
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
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Persistent session hijacking is possible in Flowintel version 3.3.0 and later because the application fails to invalidat
Remote code execution in Flowintel's alerts settings update endpoint (versions >= 3.3.0) allows an authenticated high-pr
Privilege escalation in Flowintel's administrative user-edit API allows an organization administrator to modify full adm
Remote code execution via log path traversal in Flowintel 3.3.0 and later is achievable by an authenticated administrato
Broken object-level authorization across Flowintel task endpoints allows authenticated editor-level users to perform una
Flowintel's PDF export pipeline passes attacker-controlled note content to Pandoc with the raw_tex extension enabled, al
Log injection in Flowintel versions 3.3.0 and later allows unauthenticated remote attackers to forge arbitrary log lines
Stored XSS via Vue template injection in FlowIntel allows an authenticated low-privilege user to persist malicious Vue i
Server-side request forgery in FlowIntel up to version 3.3.0 allows a low-privileged authenticated user to coerce the ap
Insufficient authorization on the Flowintel /my_assignment/user API endpoint allows any authenticated API user to retrie
Stored cross-site scripting in Flowintel's calendar view (versions >= 3.3.0) allows an authenticated user with case-crea
Stored cross-site scripting in Flowintel's MISP timeline renderer allows an authenticated low-privileged attacker to inj
EUVD-2026-67009
GHSA-4xww-rqhr-67w2
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB