CVE-2026-48768 TypeBot: Unauthenticated arbitrary s3 object write in generate-upload-url via unsanitized fileName
Unauthenticated attackers can upload malicious HTML or JS to S3 storage via unsanitized filenames, enabling stored XSS and arbitrary content hosting on the storage origin.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-48768?
CVE-2026-48768 is a critical cross-site scripting vulnerability in baptisteArno typebot.io, published on 17 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
TypeBot is a chatbot builder tool. In versions 3.16.1 and earlier, POST /api/blocks/file-input/v3/generate-upload-url is unauthenticated and uses unsanitized fileName input to construct public/ S3 object keys, while issuing presigned PUT URLs that do not bind Content-Type. As a result, any anonymous visitor to a published bot with a file input can upload attacker-controlled HTML, SVG, or JS to attacker-chosen subpaths, including other tenants’ publicly served result paths, enabling arbitrary content hosting and potential stored XSS on the storage origin. ../ traversal is blocked by S3/MinIO canonicalization (signature mismatch), but forward-slash path injection is exploitable. This issue has been fixed in version 3.17.0.
Which versions are affected by CVE-2026-48768?
How do I fix CVE-2026-48768?
No fix has been published for CVE-2026-48768 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-48768 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48768 exists.
Sources
Also known as GHSA-fp7x-6pqh-vhvf.