What it is
CVE-2025-8943 is an unauthenticated vulnerability affecting Flowise Flowise. The Custom MCPs feature is designed to execute OS commands, for instance, using tools like `npx` to spin up local MCP Servers. However,...
Vulnerability report
Active exploitation observed
Confirmed confidence
Not in CISA KEV
CVE-2025-8943
Flowise Remote Code Execution
Flowise / Flowise · affected before 3.0.1
- Severity
- CVSS 9.8 · Critical
- Confidence
- Confirmed
- Exploit status
- Observed in sensors
- EPSS
- 72.3%
- First observed
- 10 Jul 2026
- Last observed
- 05 Aug 2026
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEVIntel sensors observed exploitation attempts with confirmed confidence.
Who is affected?
Flowise / Flowise affected before 3.0.1.
What should we do?
Patch immediately, validate internet-facing exposure, and monitor for matching requests.
Overview
Flowise 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. 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.
Vendor
Product
Affected
Status
- Published
- 14 Aug 2025
- Exploitation Reported
- 10 Jul 2026
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
nuclei_scanner
CVE References
- Third-Party Advisory — research.jfrog.com research.jfrog.com · Third-Party Advisory https://research.jfrog.com/vulnerabilities/flowise-os-command-remote-...
Exploitation evidence
Why KEVIntel marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
KEVIntel
Independent exploitation attestation added to the KEVIntel record.
Active exploitation observed
KEVIntel sensor
First-party sensor telemetry confirms matching exploitation attempts.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| KEVIntel First | 2026-08-05 08:45 UTC |
Operational indicators for this CVE are listed under Detection.
Sensor telemetry
First-party evidence of exploitation activity
Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.
49
Attempts observed
26
Unique attacker IPs
11
Attacker countries
CN · DE · ES · HK · IL · IR · JP · NL · PL · SG · US
5
Sensors observed
Exploitation attempts over the last 28 days
Daily events observed by KEVIntel sensors
Updated 05 Aug 2026
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First observed 10 Jul 2026 · Last observed 05 Aug 2026
Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 1
- User-Agents
- 46
Raw values available in Pro and Enterprise.
Scanner coverage
Nuclei template detected 01 Jun 2026.
View Nuclei template (opens in new tab)Virtual patch status
No KEVIntel virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Attacker IP Indicators
Attacker IP indicators observed · available in Pro and Enterprise.
Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.
Learn about Pro API accessScanner Artifacts
Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-8943.yaml | 01 Jun 2026 |
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
9.8
Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
72.3%
Recent mention · Github Advisory Database (NPM)
[flowise-components] Flowise: CVE-2025-8943 Patch Bypass: npm_config_yes bypasses MCP environment variable blocklist (Unauthenticated RCE)
Summary The mitigation shipped for CVE-2025-8943 blocks the -y and --yes flags on npx to stop auto-installation of arbitrary packages. That flag filter works. The environment-variable check in the same patch denies only four variable names by exact string match, and npm reads...
Read full advisoryAll Mentions
Recent mention · Github Advisory Database (NPM)
[flowise-components] Flowise: CVE-2025-8943 Patch Bypass: npm_config_yes bypasses MCP environment variable blocklist (Unauthenticated RCE)Github Advisory Database (NPM) · 04 Aug 2026
Summary The mitigation shipped for CVE-2025-8943 blocks the -y and --yes flags on npx to stop auto-installation of arbitrary packages. That flag filter works. The environment-variable check in the same patch denies only four variable names by exact string match, and npm reads its configuration directly from npm_config_* environment variables. Setting npm_config_yes=true reproduces the --yes behaviour the flag filter is meant to prevent, so npx auto-installs and executes the named package. The mitigation is fully bypassed. This works with the MCP security check enabled...
Recent mention · Github Advisory Database (NPM)
[flowise] Flowise: CVE-2025-8943 Patch Bypass: npm_config_yes bypasses MCP environment variable blocklist (Unauthenticated RCE)Github Advisory Database (NPM) · 04 Aug 2026
Summary The mitigation shipped for CVE-2025-8943 blocks the -y and --yes flags on npx to stop auto-installation of arbitrary packages. That flag filter works. The environment-variable check in the same patch denies only four variable names by exact string match, and npm reads its configuration directly from npm_config_* environment variables. Setting npm_config_yes=true reproduces the --yes behaviour the flag filter is meant to prevent, so npx auto-installs and executes the named package. The mitigation is fully bypassed. This works with the MCP security check enabled...
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
Flowise < 3.0.1 - Remote Command Execution
nuclei · Created Unknown
Timeline
From disclosure to observed exploitation
-
Observed by KEVIntel sensors
Evidence-backed exploitation signal
-
Indicators of compromise added (26)
Indicators of compromise recorded
-
Public PoC available
Public proof-of-concept code published
-
Nuclei template available
Scanner coverage available
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2025-8943
Free JSON includes basic KEV fields{
"cve_id": "CVE-2025-8943",
"confidence": "Confirmed",
"cvss_score": 9.8,
"epss_score": 0.7231,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "attempts": 49, "sensors": 5 }
}