Vulnerability · Published Jun 20, 2026 · Assigned by VulnCheck

CVE-2025-71331Flowise - Cross-Site Scripting in Chat Messages and Agent Workflows

Medium 6.1

In plain English

A medium-severity security flaw in Flowise from Flowise. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.3%top 74.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Flowise before 3.0.8 contains a cross-site scripting (XSS) vulnerability caused by insufficient input filtering in chat messages and custom agent functions. An attacker can inject malicious JavaScript by sending an iframe payload (e.g., <iframe src="javascript:alert(document.cookie)">) in a chat box, or by having a custom agent function return an XSS payload from an external website. The injected script executes in the victim's browser, enabling theft of cookies and session data.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	flowise	3.0.8	GHSA-4fr9-3x69-36wv

Affected products (as reported)

Vendor	Product	Versions
Flowise	Flowise	0 – before 3.0.8

Weakness: CWE-80 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

GHSA Advisory GHSA-4fr9-3x69-36wv vendor-advisory
VulnCheck Advisory: Flowise - Cross-Site Scripting in Chat Messages and Agent Workflows third-party-advisory