RCE in Langflow
CVE-2026-33017
Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring authentication. When the optional data parameter is supplied, the endpoint uses attacker-controlled flow data (containing arbitrary Python code in node definitions) instead of the stored flow data from the database. This code is passed to exec() with zero sandboxing, resulting in unauthenticated remote code execution. This is distinct from CVE-2025-3248, which fixed /api/v1/validate/code by adding authentication. The build_public_tmp endpoint is designed to be unauthenticated (for public flows) but incorrectly accepts attacker-supplied flow data containing arbitrary executable code. This issue has been fixed in version 1.9.0.
Vulnerability class: RCE (Remote Code Execution)
EPSS: 0.962 (99.9th 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
- Langflow-ai Langflow — versions < 1.9.0
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Public proof-of-concept exploits
- MaxMnMl/langflow-CVE-2026-33017-poc
- EQSTLab/CVE-2026-33017
- z4yd3/PoC-CVE-2026-33017
- CerberusMrXi/Langflow-cve-2026-33017-exploit
- c0gnit00/CVE-2026-33017
- lxxexxbxx/CVE-2026-33017
- e4zyy/Project-CVE-2026-33017
- Industri4l-H3ll-Xpl0it3rs/CVE-2026-33017-Langflow-RCE
- Jorrit-VM/CVE-2026-33017
- omer-efe-curkus/CVE-2026-33017-Langflow-RCE-PoC
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Release Notes)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Exploit, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Press/Media Coverage)
Frequently asked questions
- What is CVE-2026-33017?
- CVE-2026-33017 is a critical-severity vulnerability in Langflow, classified under Code Injection. CVSS score: 9.8/10. Published 2026-03-20.
- How severe is CVE-2026-33017?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-33017 known to be exploited?
- Yes. CVE-2026-33017 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-25), indicating it is being actively exploited. 26 public proof-of-concept repositories are indexed.