RCE in Langflow

CVE-2026-27966

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.8.0, the CSV Agent node in Langflow hardcodes `allow_dangerous_code=True`, which automatically exposes LangChain’s Python REPL tool (`python_repl_ast`). 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). Version 1.8.0 fixes the issue.

Vulnerability class: RCE (Remote Code Execution)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.025 (84.8th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 84.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-27966: fell from 0.337 to 0.025.

EPSS over last 30 days · oldest: 0.337 · newest: 0.025 · change: -0.311

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-27966?
CVE-2026-27966 is a critical-severity vulnerability in Langflow, classified under Code Injection. CVSS score: 9.8/10. Published 2026-02-26.
How severe is CVE-2026-27966?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-27966 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.