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CVE DATABASE  /  CVE-2026-33017

CVE-2026-33017

Langflow Code Injection Vulnerability

CVSS 9.8 · CRITICAL ⚠ CISA KEV — ACTIVELY EXPLOITED
On the CISA KEV catalog

Confirmed exploited in the wild. Added 2026-03-25. Federal remediation due 2026-04-08.
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.

Summary

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 3.1 breakdown

Base score9.8 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vectorNETWORK
Attack complexityLOW
Privileges requiredNONE
User interactionNONE
ScopeUNCHANGED
ConfidentialityHIGH
IntegrityHIGH
AvailabilityHIGH

Weakness type (CWE)

Affected products

Langflow langflow
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References

Data: NIST NVD + CISA KEV. NVD last modified 2026-05-21. Always verify against the vendor advisory before acting.

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