SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-8943

The Custom MCPs feature is designed to execute OS commands, for instance, using tools like `npx` to spin up local MCP Servers.

CRITICAL 9.8EPSS 66.3%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 66.3%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.

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.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
66.30% probability · 99th percentile
CISA KEV
Not listed
Weakness
CWE-306, CWE-862
Affected
flowiseai/flowise
Source
reefs@jfrog.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.