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

Status: published. Published: 2026-06-20. Updated: 2026-11-08.

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.

## Remediation

- fix: flowise (npm): OSV reports a fixed version 3.0.8. Check the advisory for supported release branches. (source: OSV GHSA-4fr9-3x69-36wv) — https://github.com/advisories/GHSA-4fr9-3x69-36wv

## Affected products and versions

- Flowise / Flowise (flowise): ≥ 0; < 3.0.8 (affected, semver); 3.0.8 (unaffected, semver). Source: CNA: VulnCheck
-  / flowise (flowise): ≥ 0; < 3.0.8 (affected, semver); OSV events: introduced 0; fixed 3.0.8. Source: OSV GHSA-4fr9-3x69-36wv

## Severity and prioritization

- CVSS 4.0: 5.1 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 6.1 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.33% as of 2026-11-08; percentile 25.74%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-80

## Exploit evidence

- exploit: https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-4fr9-3x69-36wv (ADP: CISA-ADP)

## References

- https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-4fr9-3x69-36wv (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/flowise-cross-site-scripting-in-chat-messages-and-agent-workflows (CNA: VulnCheck; third-party-advisory)

- https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-4fr9-3x69-36wv (ADP: CISA-ADP; exploit)

- https://github.com/advisories/GHSA-4fr9-3x69-36wv (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-4fr9-3x69-36wv (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2025-71331; retrieved 2026-11-08; source updated 2026-11-08

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-4fr9-3x69-36wv; retrieved 2026-11-08; source updated 2026-07-08

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2025-71331; retrieved 2026-11-08; source updated Not reported

Revision: e9272c10599af0c68ab736269f4a01ad20181eec17d7cc449c07ac8f62b1654d

Canonical: https://y2.dev/cve/CVE-2025-71331

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.