CVSS 3.1
9.9 criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HCVE-2026-33309
Critical (9.9) in langflow langflow. EPSS 13% chance of exploitation in the next 30 days. Fixed in langflow 1.9.0.
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.
Severity
- EPSS
- 13% chance of exploitation in the next 30 days; higher than 96% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-22, CWE-73, CWE-94, CWE-284
- Published
- Modified
- Record from
- the NVD, synced
Affected
- langflow:langflow
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-g2j9-7rj2-gm6c | PyPI | langflow | >=1.2.0 <1.9.0 | 1.9.0 |
| PYSEC-2026-79 | PyPI | langflow | >=1.2.0 <1.9.0 | 1.9.0 |