CVE-2026-33017: Langflow Code Injection Vulnerability

In short

Langflow Langflow has a weakness classified as code injection (CWE-94). CISA added it to its Known Exploited Vulnerabilities catalog on 2026-03-25. NVD lists CVSS 4.0 at 9.3 CRITICAL.

What it is

“Langflow contains a code injection vulnerability that could allow building public flows without requiring authentication.” — CISA KEV, retrieved 2026-11-01

“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.” — NVD, retrieved 2026-11-01

Who is affected

Langflow Langflow. NVD lists the following versions as affected:

• Versions before 1.8.2

Exploitation status

CISA KEV added: 2026-03-25. Known ransomware campaign use: Not reported by CISA. Due date CISA set for US federal civilian agencies: 2026-04-08.

Scores

NVD CVSS 4.0: 9.3 CRITICAL; vector 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; source [email protected].

EPSS by FIRST: 96.18%; percentile 99.88; score date 2026-10-31. EPSS estimates the probability of exploitation in the next 30 days.

CWE: CWE-94, CWE-95, CWE-306.

Timeline

CISA 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.” — CISA KEV

What to do

• Confirm whether you run Langflow Langflow and which version.
• Apply the vendor update or mitigation in the advisory.
• Follow CISA’s required action.
• Review the vendor guidance on signs of compromise.
• Track the fix through completion.

References

• Third Party Advisory: https://github.com/advisories/GHSA-rvqx-wpfh-mfx7
• Patch: https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0
• Release Notes: https://github.com/langflow-ai/langflow/releases/tag/1.8.2
• NVD detail
• CVE.org record
• CISA KEV catalog

Sources and dates

CISA Known Exploited Vulnerabilities Catalog, version 2026.10.30; retrieved 2026-11-01. CISA KEV data: CC0 1.0. No endorsement by CISA.

NVD retrieved: 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.

EPSS scores by FIRST; score date 2026-10-31.