Auth bypass in Baptistearno Typebot.io

CVE-2026-48763

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.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L.

EPSS exploit prediction

EPSS: 0.005 (42.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.2% 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-2026-48763: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-48763?
CVE-2026-48763 is a high-severity vulnerability in Baptistearno Typebot.io, classified under Missing Authorization. CVSS score: 8.2/10. Published 2026-08-11.
How severe is CVE-2026-48763?
High severity. CVSS v3 base score is 8.2 out of 10.