CVE-2026-42157
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedFlowsint is an open-source OSINT graph exploration tool designed for cybersecurity investigation, transparency, and verification. Prior to 1.2.3, a remote attacker can create a map node with a malicious label that contains arbitrary HTML. When the map tab is selected and a map node marker is selected, it will render the arbitrary HTML, potentially triggering stored XSS. This vulnerability is fixed in 1.2.3.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThis is a stored XSS vulnerability in Flowsint (OSINT graph exploration tool) prior to version 1.2.3. A remote attacker can create map nodes with malicious HTML labels that execute when users view the map tab and select node markers.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- Authentication
- X
- User interaction
- P
- Scope
- X
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Flowsint versionLocate the installed Flowsint application and check its version number (typically accessible via the application UI, about section, or software inventory)Affected if Version is below 1.2.3 (for example, 1.2.2, 1.2.1, 1.2.0, or earlier)
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Verify map feature usageConfirm that the Flowsint map tab functionality has been used to create or import graph nodesAffected if Map nodes exist in the application database or project files
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Inspect map node labelsAccess the Flowsint data storage (database or project files where node data is persisted) and examine the label field values for map nodesAffected if Node labels contain unsanitized HTML tags such as <script>, <img>, <svg>, or event handlers like onclick/onerror
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Check for stored XSS payloadsSearch node label data for common XSS injection patterns including script tags, javascript: URIs, or HTML event attributesAffected if Node labels contain patterns typical of XSS payloads rather than plain text labels
User is affected if Flowsint version is below 1.2.3 AND the map feature has been used with node data that may contain unsanitized HTML in labels.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to Flowsint version 1.2.3 or later which includes input sanitization for map node labels.
Flowsint version 1.2.3
- 1. Identify the current installed version of Flowsint
- 2. Backup the existing Flowsint installation and any associated data
- 3. Update Flowsint to version 1.2.3 or later using the project's recommended upgrade method
- 4. Verify that the application runs without errors after upgrade
- 5. Test that map nodes properly sanitize HTML in labels (the XSS vulnerability should be fixed)
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-42157 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-42157 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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