Critical Multi-Tenant Variable Disclosure in Flowise Cloud via Custom JavaScript Function

published 2025-09-22 13 mo ago modified 2026-10-11 28 d ago also EUVD-2025-30835

cvss: 9.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 4.0%; EPSS 4.0% chance of exploitation in 30 days, percentile 90%
public exploits: 0; none known

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to August 2025 Cloud-Hosted Flowise, an authenticated vulnerability in Flowise Cloud allows any user on the free tier to access sensitive environment variables from other tenants via the Custom JavaScript Function node. This includes secrets such as OpenAI API keys, AWS credentials, Supabase tokens, and Google Cloud secrets — resulting in a full cross-tenant data exposure. This issue has been patched in the August 2025 Cloud-Hosted Flowise.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 13 mo ago (2025-09-22)

Exploit prediction

4.03% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected products

FlowiseAI Flowise

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-284 Improper Access Control

References

github.com /FlowiseAI/Flowise/security/advisories/GHSA-435c-mg9p-fv22

Sources

CVE List CVE-2025-59434
NVD CVE-2025-59434

Fencer Vulns 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.

Summary