What is CVE-2026-27966?

CVE-2026-27966 is a critical-severity vulnerability in Langflow-ai 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?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

RCE in Langflow-ai 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_…

Vulnerability class: RCE (Remote Code Execution)

EPSS: 0.410 (97.5th percentile) — read the EPSS interpretation.

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.

Affected products

Langflow-ai Langflow — versions < 1.8.0

Weakness classification (CWE)

CWE-94 — Code Injection

Public proof-of-concept exploits

References

https://github.com/langflow-ai/langflow/security/advisories/GHSA-3645-fxcv-hqr4 (x_refsource_CONFIRM)
https://github.com/langflow-ai/langflow/commit/d8c6480daa17b2f2af0b5470cdf5c3d28dc9e508 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-27966?: CVE-2026-27966 is a critical-severity vulnerability in Langflow-ai 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?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.