CVE-2026-33309
9.9 · CRITICALOverview
CVE-2026-33309 is a critical-severity vulnerability affecting langflow langflow. It was published on March 24, 2026 and has a CVSS 3.1 base score of 9.9 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.9, rated CRITICAL. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
Langflow is a tool for building and deploying AI-powered agents and workflows. Versions 1.2.0 through 1.8.1 have a bypass of the patch for CVE-2025-68478 (External Control of File Name), leading to the root architectural issue within `LocalStorageService` remaining unresolved. Because the underlying storage layer lacks boundary containment checks, the system relies entirely on the HTTP-layer `ValidatedFileName` dependency. This defense-in-depth failure leaves the `POST /api/v2/files/` endpoint vulnerable to Arbitrary File Write. The multipart upload filename bypasses the path-parameter guard, allowing authenticated attackers to write files anywhere on the host system, leading to Remote Code Execution (RCE). Version 1.9.0 contains an updated fix.
Remediation
Check the references section for vendor advisories and patches from langflow. Update langflow to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| langflow | langflow | >= 1.2.0, < 1.9.0 | Affected |
Frequently Asked Questions
What is CVE-2026-33309?
CVE-2026-33309 is a critical-severity vulnerability affecting langflow langflow. It was published on March 24, 2026 and has a CVSS 3.1 base score of 9.9 (CRITICAL).
How severe is CVE-2026-33309?
This vulnerability has a CVSS 3.1 base score of 9.9, rated CRITICAL. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-33309?
Check the references section for vendor advisories and patches from langflow. Update langflow to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-33309?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-33309 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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