CVE-2026-39970
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 · uneditedTypeBot is a chatbot builder tool. Versions 3.15.2 and prior contain a critical stored XSS vulnerability in the app.typebot.io profile picture upload form. The application fails to sanitize or restrict SVG/XML-based uploads and directly renders them when accessed through the domain. By uploading a crafted malicious SVG file containing embedded JavaScript, an attacker will execute arbitrary JavaScript code. This vulnerability directly enables stored XSS exploitation because the payload is persistently stored on your infrastructure (app.typebot.io) and accessible from a public-facing, permanent link. Stored XSS via malicious SVG uploads to app.typebot.io allows attackers to execute arbitrary JavaScript in victims' browsers, enabling session/token theft, account takeover, and exfiltration of sensitive user data. This issue has been fixed in version 3.16.0.
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 confidenceTypeBot versions 3.15.2 and prior contain a stored XSS vulnerability in the profile picture upload functionality. The application accepts and renders SVG files without sanitization, allowing attackers to embed malicious JavaScript that executes when victims view the uploaded image. The payload persists on the app.typebot.io infrastructure, enabling permanent, public-facing exploitation.
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:H/VI:H/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 the installed TypeBot versionCheck the package.json file or the application startup logs for the TypeBot version number. Look for a 'version' field in the codebase or run 'npm list typebot' in the installation directory.Affected if The version is 3.15.2 or any earlier version (3.x.x where x.x is less than 3.15.2).
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Verify profile picture upload feature existsLog into the TypeBot admin interface and navigate to user profile settings. Look for an option to upload or change a profile picture.Affected if The profile picture upload feature is available and accessible to users.
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Confirm SVG file upload is permittedAttempt to upload an SVG file as a profile picture through the web interface or API endpoint. Verify the server accepts and stores the file without rejecting SVG format.Affected if The application accepts SVG files for profile picture uploads without blocking or sanitizing them.
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Inspect how uploaded profile images are servedAfter uploading an SVG, access the image URL directly in a browser. Check the response headers and content-type to see if the SVG is served as 'image/svg+xml' or rendered inline.Affected if The uploaded SVG is served directly with its original content intact (content-type: image/svg+xml) rather than being sanitized or converted to another format.
A self-hosted TypeBot instance is affected if it runs version 3.15.2 or prior and allows users to upload profile pictures as SVG files without sanitization.
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 TypeBot to version 3.16.0 or later to resolve the insufficient input validation. Consider implementing additional controls such as restricting SVG uploads to trusted file types or applying server-side sanitization to uploaded content.
Upgrade to TypeBot version 3.16.0 or later
- Identify all TypeBot deployments running version 3.15.2 or prior that have profile picture upload functionality exposed
- Back up the TypeBot database and configuration files before performing the upgrade
- Upgrade TypeBot to version 3.16.0 or later by following the official upgrade documentation
- After upgrading, verify the version number in the application settings to confirm the upgrade was successful
- Test the profile picture upload feature with a valid image file to ensure the upload functionality continues to work correctly
- Clear any cached assets or CDN content that may contain old versions of the application
- Monitor application logs for any unusual activity or attempted exploitation attempts
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-39970 — 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-2026-39970 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
- No spam, self-promotion, credentials, or personal data