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Fencer Intel
critical 9.3

CVE-2026-48768 json

TypeBot: Unauthenticated arbitrary s3 object write in generate-upload-url via unsanitized fileName

published 4mo ago modified 16d ago also EUVD-2026-37829

cvss
9.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

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.

Patch / fix

  • typebot typebot 3.17.0

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
4mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-fp7x-6pqh-vhvf referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N

Affected products

  • baptisteArno typebot.io

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.