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Fencer Intel
high 8.2

CVE-2026-48763 json

TypeBot has Arbitrary S3 Object Write in deprecated public upload endpoint via attacker-controlled filePath

published 3mo ago modified 19d ago also EUVD-2026-56979

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

TypeBot is a chatbot builder tool. Versions prior to 3.17.0 expose a deprecated public upload endpoint at `GET /api/v1/typebots/{typebotId}/blocks/{blockId}/storage/upload-url` that accepts an attacker-controlled `filePath` and returns a presigned S3 `PUT` URL for that exact key. Because the endpoint only checks that the referenced typebot is public and that the referenced block is a file input block, an unauthenticated attacker who knows a valid public `typebotId` and `blockId` can request presigned upload URLs for arbitrary objects in the shared bucket, including `private/...` and other tenants' `public/...` paths. Version 3.17.0 fixes this issue.

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
2mo ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-m7f5-3wcm-x2c4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

Affected products

  • baptisteArno typebot.io

Classification

Weakness

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.