CVE-2026-50132: Budibase: Chat Identity Link Hijacking via Missing Consent & CSRF — Account Impersonation in Budibase

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-26 · updated 2026-06-30
Weakness: CWE-284

Description

Budibase is an open-source low-code platform. Prior to 3.39.0, `GET /api/chat-links/:instance/:token/handoff` is a public endpoint (no auth required) that performs a permanent, state-changing operation: it binds an external chat identity (Slack/Discord/MS Teams) to an authenticated Budibase user account, with no consent UI and no CSRF protection. The session token in the URL is created by the attacker (from their own /link slash command) and embeds the attacker's externalUserId. When an authenticated Budibase victim visits the URL, their account is silently and permanently linked to the attacker's Slack/Discord identity. The server responds with "Authentication succeeded." — no indication of what was linked. This vulnerability is fixed in 3.39.0.

Affected products

budibase: before 3.39.0 — fixed in 3.39.0

How to fix

Upgrade to a fixed version: budibase 3.39.0. Check the vendor advisory for mitigations.

References

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