CVE-2026-33017
Langflow has Unauthenticated Remote Code Execution via Public Flow Build Endpoint
At a glance
- Source
- NVD
- EPSS
- EPSS 96.18 % · percentile 100 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
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.
Weaknesses (CWE)
- CWE-94 — Improper Control of Generation of Code
- CWE-95 — Improper Neutralization of Directives in Dynamically Evaluated Code
- CWE-306 — Missing Authentication for Critical Functionality
References
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx
- https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0
- https://github.com/advisories/GHSA-rvqx-wpfh-mfx7
- https://www.sysdig.com/blog/cve-2026-33017-how-attackers-compromised-langflow-ai-pipelines-in-20-hours
- https://medium.com/@aviral23/cve-2026-33017-how-i-found-an-unauthenticated-rce-in-langflow-by-reading-the-code-they-already-dc96cdce5896
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-33017
- https://github.com/langflow-ai/langflow/releases/tag/1.8.2
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | CRITICAL 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L | GitHub_M |
| CVSS 4.0 | CRITICAL 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-vwmf-pq79-vjvx — Unauthenticated Remote Code Execution in Langflow via Public Flow Build Endpoint
- PYSEC-2026-379 — Unauthenticated Remote Code Execution in Langflow via Public Flow Build Endpoint
European references
- ENISA EUVD · EUVD-2026-13556
- GCVE · GCVE-0-2026-33017
Affected configurations (NVD CPE)
cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:*< 1.8.2
Affected products
| Product | Versions |
|---|---|
| langflow-ai · langflow | affected < 1.9.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| CISA Known Exploited Vulnerabilities | CC0 1.0 |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |