CVE-2026-33017
Langflow Code Injection Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 8 April 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 4.0
- 9.3 CRITICALCVSS: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/M
- EPSS
- 96.18% probability · 100th percentile
- CISA KEV
- Listed 25 March 2026 · due 8 April 2026
- Weakness
- CWE-94, CWE-95, CWE-306
- Affected
- langflow/langflow
- Source
- security-advisories@github.com
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx ; https://nvd.nist.gov/vuln/detail/CVE-2026-33017
References
- https://github.com/advisories/GHSA-rvqx-wpfh-mfx7Third Party Advisory
- https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0Patch
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvxExploit, Mitigation, Vendor Advisory
- https://github.com/langflow-ai/langflow/releases/tag/1.8.2Release Notes
- https://medium.com/@aviral23/cve-2026-33017-how-i-found-an-unauthenticated-rce-in-langflow-by-reading-the-code-they-already-dc96cdce5896Exploit, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-33017US Government Resource
- https://www.sysdig.com/blog/cve-2026-33017-how-attackers-compromised-langflow-ai-pipelines-in-20-hoursPress/Media Coverage
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.