CVE-2025-8943 — flowise
CRITICALCVE-2025-8943 is a critical-severity (CVSS 9.8) Missing Authentication vulnerability in flowise. EPSS puts its 30-day exploitation probability at 75.3% (100th percentile). The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
Unsupervised OS command execution leads to remote code execution by unauthenticated network attackers
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-8943.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
flowisenpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | flowise | all versions | No fix |
Affected Products
flowiseflowiseaiDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flowise, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of flowise for CVE-2025-8943. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
How to detect CVE-2025-8943
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2025-8943 -u https://target- Template
- Flowise < 3.0.1 - Remote Command Execution
- Severity
- critical
- Impact
- Successful exploitation allows attackers to execute arbitrary OS commands on the target server, potentially leading to complete system compromise, data theft, and lateral movement within the network.
- Remediation
- Update Flowise to the latest version that addresses this vulnerability. Implement proper input validation and sanitization for the customMCP endpoint parameters.
Template by ProjectDiscovery nuclei-templates (zezezez), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2025-8943 in your dependencies?
Find it across npm, including transitive dependencies.