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Fencer Intel
medium 6.5

CVE-2026-39966 json

TypeBot: Async filter() bypasses authorization, allowing IDOR in getLinkedTypebots and leaking cross-workspace bot definitions

published 5mo ago modified 3mo ago also EUVD-2026-31482

cvss
6.5
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 17%
public exploits
0
none known

Summary

TypeBot is a chatbot builder tool. In versions 3.15.2, the getLinkedTypebots API endpoint returns full bot definitions to any authenticated user who references a target bot ID in a Typebot Link block, regardless of workspace ownership, leading to IDOR. The authorization check uses Array.filter() with an async callback — since filter() is synchronous, the callback always returns a truthy Promise, so the access control predicate is never actually evaluated. Any authenticated Typebot user can read the full definition of any other workspace's private bots, including: all conversation blocks and logic flow, variable values embedded in the bot (credentials, API keys, PII), webhook URLs and integration configurations. This issue has been fixed in version 3.16.0.

Patch / fix

Is CVE-2026-39966 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
5mo ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-3fr5-999r-84qj referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

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.