CVE-2026-69255: Flowise: CSV Agent Remote Code Execution via Pyodide Code Injection — Root Shell Verified

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. 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 0.6%, percentile 48: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 48% of all scored CVEs (low). 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) <= 3.1.2, fixed in 3.1.3; flowise-components (npm) <= 3.1.2, fixed in 3.1.3. Check your lockfile, including transitive dependencies.

What it is

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the CSVAgent in packages/components/nodes/agents/CSVAgent/CSVAgent.ts extracted attacker-controlled CSV data with file.split(',').pop() and interpolated it directly into executable Python as base64string = "${base64String}" before calling Pyodide. The validatePythonCodeForDataFrame() denylist only checked later LLM-generated code and did not validate this initial code block. An authenticated attacker could inject a closing quote followed by Python code, use Pyodide's js bridge to load Node.js childprocess, and execute arbitrary operating system commands as root in the Flowise container. This issue is fixed in version 3.1.3.

From the GitHub advisory

UPDATE 2026-05-20: Full RCE as root VERIFIED

This is not theoretical — a Meterpreter reverse shell session as root has been established on Flowise 3.1.2.

Verified Exploit Chain

1. Python code injection via base64string = "${base64String}" (CSVAgent.ts line 161) 2. Pyodide js bridge provides access to the host Node.js process 3. process.mainModule.constructor.load('childprocess') loads childprocess (bypasses ESM require restriction) 4. .execSync('CMD') executes arbitrary OS commands as root (PID 1 in container)

Working RCE Payload

Weakness type: CWE-94.

Product: flowise (npm) · Assigned by: GitHub_M · Published: 2026-08-04

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: present (depends on deployment conditions)
• Privileges required: none (no login)
• User interaction: none

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 no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.60% probability of exploitation activity in the next 30 days; percentile 48.

Timeline

• 2026-08-04 — CVE record last updated
• 2026-08-04 — CVE record published by GitHub_M
• 2026-08-04 — GitHub-reviewed advisory GHSA-vmv7-4m6c-3cg5 published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-vmv7-4m6c-3cg5 github.com
2. CVE.org record CVE-2026-69255 cve.org
3. NVD entry CVE-2026-69255 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com

Critical npm advisories · Today’s Security Digest