Langflow Vulnerability CVE-2026-5027 Exploited for Unauthenticated RCE

Summary: VulnCheck found active exploitation of CVE-2026-5027, a path traversal flaw (CVSS 8.8) in Langflow's 'POST /api/v2/files' endpoint that fails to sanitize the 'filename' parameter, allowing file writes to arbitrary locations; Tenable, which discovered the bug, disclosed it on March 27, 2026 after three failed contact attempts with maintainers in January and February. VulnCheck's Caitlin Condon said the flaw enables unauthenticated remote code execution because Langflow auto-login is on by default, and Censys counts roughly 7,000 Langflow instances exposed on the internet, mostly in North America.
Key Takeaway: A single unauthenticated request is enough to get a session token and reach the vulnerable endpoint, and the fix only arrived in Langflow 1.9.0 on April 15, 2026 - leaving roughly 7,000 exposed instances to be patched against a bug already being exploited in the wild.

Read the original at The Hacker News ↗

Topics: Vulnerabilities & Patching
Mentions: CVE-2025-34291 CVE-2026-0770 CVE-2026-21445 CVE-2026-33017 CVE-2026-5027
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