# CVE-2025-8943: Flowise - RCE

> Live exploitation tracking for CVE-2025-8943 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2025-8943

## Key facts

- **Exploitation phase:** Background Noise. Continuous low-level scanning or exploitation attempts are observed, mostly opportunistic and automated.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** Flowise
- **Weaknesses:** CWE-862 (Missing Authorization); CWE-306 (Missing Authentication for Critical Function)
- **Tags:** enterprise_software

## Description

The Custom MCPs feature is designed to execute OS commands, for instance, using tools like `npx` to spin up local MCP Servers. However, Flowise's inherent authentication and authorization model is minimal and lacks role-based access controls (RBAC). Furthermore, in Flowise versions before 3.0.1 the default installation operates without authentication unless explicitly configured. This combination allows unauthenticated network attackers to execute unsandboxed OS commands.

## CrowdSec analysis

[CVE-2025-8943](https://euvd.enisa.europa.eu/vulnerability/CVE-2025-8943) is a critical vulnerability in Flowise versions prior to 3.0.1, where the lack of default authentication and absence of role-based access controls allow unauthenticated attackers to execute arbitrary OS commands remotely. This flaw exposes affected systems to severe risks, including remote code execution, data theft, and full system compromise.

CrowdSec has been tracking this vulnerability and its exploits since 19th of November 2025.

CrowdSec network data shows that most actors exploiting CVE-2025-8943 rely on broad, untargeted scans with minimal filtering. The activity is largely automated and opportunistic in nature.
CrowdSec data also reveals a clear uptick in attacks involving CVE-2025-8943 over the past week. Activity is above the usual baseline, suggesting growing attention from attackers. This may reflect rising awareness, recent exploit releases, or expanded targeting efforts.

Attackers exploit the `/api/v1/node-load-method/customMCP` endpoint by sending crafted JSON payloads to execute arbitrary OS commands, leveraging weak or absent authentication in vulnerable Flowise installations.

## Timeline

- 2025-08-14: CVE Published. CVE-2025-8943 is published to NVD.
- 2025-11-19: Rule Released. CrowdSec releases a rule to detect CVE-2025-8943 exploitation attempts against the CrowdSec Network.
- 2025-11-27: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2025-8943 for the first time.

## References

- https://research.jfrog.com/vulnerabilities/flowise-os-command-remote-code-execution-jfsa-2025-001380578/
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-8943.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2025-8943) follows observed exploitation activity for CVE-2025-8943. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.