Resource exhaustion in Langflow - CVE-2026-55446
Published: June 19, 2026
Vulnerability identifier: #VU134971
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-55446
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in the /api/v1/files/upload/ endpoint when processing multipart form data. A remote attacker can send a specially crafted file upload request with an excessively long multipart boundary to cause a denial of service.
The server processes the malformed multipart body before authentication and before validating whether the supplied flow identifier is valid.
Affected software
Langflow
How to mitigate CVE-2026-55446
Install security update from vendor's website.
Langflow - update to 1.0.19