XSS in Baptistearno Typebot.io

CVE-2026-48768

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (32.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-48768: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-48768?
CVE-2026-48768 is a critical-severity vulnerability in Baptistearno Typebot.io, classified under Path Traversal. CVSS score: 9.3/10. Published 2026-06-18.
How severe is CVE-2026-48768?
Critical severity. CVSS v3 base score is 9.3 out of 10.