MSRXCVE-2026-33017
CVE-2026-33017
Langflow has Unauthenticated Remote Code Execution via Public Flow Build Endpoint
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CVSS 4.0 · CNA
chance of exploitation in the next 30 days (EPSS; in the top 1% of all CVEs)
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.
Affected packages and fixed versions
| Package | Ecosystem | Fixed in |
|---|---|---|
| langflow | PyPI | 1.9.0 |
Affected products
- langflow-ai langflow: < 1.9.0
Weakness: CWE-94, CWE-95, CWE-306
Also known as: GHSA-vwmf-pq79-vjvx, PYSEC-2026-379
3 references (advisories, patches, write-ups)
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx · x_refsource_CONFIRM
- https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0 · x_refsource_MISC
- https://github.com/advisories/GHSA-rvqx-wpfh-mfx7 · x_refsource_MISC
Sources: CVE.org, OSV.dev, FIRST EPSS. Missing ones did not answer or have no record yet.