Flowise: Improper Mass Assignment in Account Registration Enables Unauthorized Organization Association

published 2026-04-16 6 mo ago modified 2026-10-26 13 d ago also GHSA-48m6-ch88-55mj , EUVD-2026-25284

cvss: 8.1; 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 26%
public exploits: 0; none known

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.0, an improper mass assignment (JSON injection) vulnerability in the account registration endpoint of Flowise Cloud allows unauthenticated attackers to inject server-managed fields and nested objects during account creation. This enables client-controlled manipulation of ownership metadata, timestamps, organization association, and role mappings, breaking trust boundaries in a multi-tenant environment. This vulnerability is fixed in 3.1.0.

Patch / fix

fixed in 2

npm flowise 3.1.0
flowiseai flowise 3.1.0

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 6 mo ago (2026-04-23)

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-48m6-ch88-55mj referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub	3.0	8.1	CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	flowise	<3.1.0	3.1.0

Affected products

FlowiseAI Flowise

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key
CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes
CWE-20 Improper Input Validation

References

github.com /FlowiseAI/Flowise/security/advisories/GHSA-48m6-ch88-55mj
exploit, web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2026-41267
advisory
github.com /FlowiseAI/Flowise
package

Sources

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