Langflow is a tool for building and deploying AI-powered agents and workflows.
CVE-2026-27966
1. Summary The CSV Agent node in Langflow hardcodes allowdangerouscode=True, which automatically exposes LangChain’s Python REPL tool (pythonreplast). As a result, an attacker can execute arbitrary Python and OS commands on the server via prompt injection, leading to full Remote Code Execution (RCE). 2. Description 2.1 Intended Functionality When building a flow such as ChatInput → CSVAgent → ChatOutput, users can attach an LLM and specify a CSV file path. The CSV Agent then provides capabilities to query, summarize, or manipulate the CSV content using an LLM-driven agent. 2.2 Root Cause In src/lfx/src/lfx/components/langchainutilities/csvagent.py, the CSV Agent is instantiated as follows: python agentkwargs = { "verbose": self.verbose, "allowdangerouscode": True, # hardcoded } agentcsv = createcsvagent(..., agentkwargs) Because allowdangerouscode is hardcoded to True, LangChain automatically enables the pythonreplast tool. Any LLM output that issues an action such as: Action: pythonreplast Action Input: import("os").system("echo pwned > /tmp/pwned") is executed directly on the server. There is no UI toggle or environment variable to disable this behavior. 3. Proof of Concept…
A ready-made exploit module exists
Metasploit · Public PoC
- Metasploitexploit/multi/http/langflow_rce_cve_2026_27966
- Public PoCAnon-Cyber-Team/CVE-2026-27966--RCE-in-Langflow2 stars
- Public PoCshinthink/CVE-2026-279662 stars
Signals come from Exploit-DB, Metasploit, Nuclei and published proof-of-concept repositories. Their absence means nothing was found, not that nothing exists.
Part of the AI stack
This affects Langflow, in Agent frameworks.
Assessment
- CVSS
- 9.8 (v3.1)
- Severity
- Critical
- EPSS
- 35.25% chance of exploitation in the next 30 days
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Metasploit, Public PoC
- Published
- 26 February 2026
- Last updated
- 27 October 2026
- Affected
- langflow-ai · langflow · langflow
- Weakness
- CWE-94
- Assigner
- security-advisories@github.com
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
At the source
References
- https://github.com/langflow-ai/langflow/commit/d8c6480daa17b2f2af0b5470cdf5c3d28dc9e508
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-3645-fxcv-hqr4
- https://nvd.nist.gov/vuln/detail/CVE-2026-27966
- https://github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2026-376.yaml
- https://pypi.org/project/langflow
- https://github.com/advisories/GHSA-3645-fxcv-hqr4
Community proofs of concept
No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.
Submit a proof of concept
Only for publicly disclosed vulnerabilities, and only material from testing you were authorised to perform. This platform does not buy, sell, or broker exploits — see earning from vulnerability research for legitimate bounty programs. Submissions are reviewed before they appear. Text only; do not include live credentials, personal data, or anything targeting systems you are not permitted to test.
Query this programmatically
Agents can read this through the MCP endpoint, or over HTTP:
curl https://cve.zerocrew.in/api/cve/CVE-2026-27966