CVE-2025-71331

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.

CVSS 4.0

5.1CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS 3.1

6.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 25% of CVEs (scores of 2026-10-25)

CWE

CWE-80

Published

2026-06-20

Modified

2026-10-19

Record from

the NVD, synced 2026-10-19

Affected

• flowiseai:flowise

Packages (OSV)

References

• https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-4fr9-3x69-36wv
• https://www.vulncheck.com/advisories/flowise-cross-site-scripting-in-chat-messages-and-agent-workflows
• https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-4fr9-3x69-36wv

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