Security Digest · Vulnerability record
CVE-2025-8943: Flowise OS command remote code execution
The Custom MCPs feature is designed to execute OS commands, for instance, using tools like npx to spin up local MCP Servers.
CVSS 9.8 Critical EPSS 75.2% · p99.5
Should you act?
High exploit likelihood
EPSS ranks it in the top 5% of all CVEs for likely exploitation in the next 30 days. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 75.2%, percentile 99.5: FIRST’s model estimates a 75.2% chance of exploitation activity in the next 30 days, higher than 99.5% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
flowise(npm) <= 3.0.5, no fixed version listed. Check your lockfile, including transitive dependencies.
What it is
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.
From the GitHub advisory
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.
Weakness type: CWE-306, CWE-862, CWE-78.
Product: flowise (npm) · Assigned by: JFROG · Published: 2025-08-14
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | flowise | <= 3.0.5 | none listed |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| flowise | < 3.0.1 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| JFROG | 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: unchanged
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 75.20% probability of exploitation activity in the next 30 days; percentile 99.5.
Timeline
- — CVE record published by JFROG
- — GitHub-reviewed advisory GHSA-2vv2-3x8x-4gv7 published (critical)
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-2vv2-3x8x-4gv7 github.com
- CVE.org record CVE-2025-8943 cve.org
- NVD entry CVE-2025-8943 nvd.nist.gov
Other references from the CVE record and advisory
- research.jfrog.com research.jfrog.com