Flowise - RCE (CVE-2025-8943)

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.

Data from the CrowdSec community indicates that exploitation of CVE-2025-8943 is highly selective and intelligence-driven. Threat actors use advanced reconnaissance and carefully choose their targets, often as part of sophisticated campaigns or advanced persistent threat operations. 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.