RCE in Langflow

CVE-2026-33873

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.9.0, the Agentic Assistant feature in Langflow executes LLM-generated Python code during its validation phase. Although this phase appears intended to validate generated component code, the implementation reaches dynamic execution sinks and instantiates the generated class server-side. In deployments where an attacker can access the Agentic Assistant feature and influence the model output, this can result in arbitrary server-side Python execution. Version 1.9.0 fixes the issue.

Vulnerability class: RCE (Remote Code Execution)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.018 (78.3th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.3% 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-2026-33873: held from 0.014 to 0.018.

EPSS over last 30 days · oldest: 0.014 · newest: 0.018 · change: +0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33873?
CVE-2026-33873 is a critical-severity vulnerability in Langflow, classified under Code Injection. CVSS score: 9.9/10. Published 2026-03-27.
How severe is CVE-2026-33873?
Critical severity. CVSS v3 base score is 9.9 out of 10.