Unpatched Langflow CVE-2026-5027 Exploited in the Wild
Summary
VulnCheck says attackers are exploiting unpatched Langflow CVE-2026-5027, a path-traversal flaw in /api/v2/files that allows arbitrary file writes and may enable RCE. Censys found about 7,000 publicly exposed instances.
Key points
- CVE-2026-5027 is an unpatched Langflow path-traversal flaw with a CVSS score of 8.8.
- Tenable says the POST /api/v2/files endpoint fails to sanitize the multipart form's filename parameter, allowing path-traversal sequences to write files to arbitrary locations.
- VulnCheck reports active exploitation; its vice president of security research says the flaw can enable remote code execution.
- According to the article, Langflow's default unauthenticated auto-login can let an attacker obtain a session token without credentials before exploiting the endpoint.
- Observed exploitation efforts appear to be writing test files to victim systems, the article says.
- Censys data shows about 7,000 Langflow instances are publicly exposed, most in North America.
Article Details
- Vulnerability Types
- Path traversal
- Arbitrary file write
- Severity
- High (CVSS 8.8)
- Exploitation Status
- active
- Exploit Availability
- unknown
- Patch Status
- unavailable
MITRE ATT&CK
CVE
CVE-2025-34291Langflow · LangflowThe issue affects publicly exposed Langflow instances, and exploitation activity adds to a series of recent attacks against Langflow vulnerabilities, including CVE-2025-34291 used by MuddyWater.CVE-2026-0770Langflow · Langflowa flurry of exploitation activity targeting other Langflow vulnerabilities this year, including CVE-2026-0770, CVE-2026-33017, CVE-2026-21445, and CVE-2025-34291, the last of which has been weaponized by theCVE-2026-21445Langflow · Langflowactivity targeting other Langflow vulnerabilities this year, including CVE-2026-0770, CVE-2026-33017, CVE-2026-21445, and CVE-2025-34291, the last of which has been weaponized by the Iranian state-sponsored group knownCVE-2026-33017langflow-ai · langflowof exploitation activity targeting other Langflow vulnerabilities this year, including CVE-2026-0770, CVE-2026-33017, CVE-2026-21445, and CVE-2025-34291, the last of which has been weaponized by the IranianCVE-2026-5027langflow-ai · langflowLangflow is being actively exploited in the wild through CVE-2026-5027, a high-severity path traversal flaw that can let attackers write files to arbitrary locations and potentially achieve remote code execution.