CVE-2026-55446

Langflow: Unauthenticated DoS through multipart form boundary file upload

Published Jun 23, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.0.19, an attacker can send a /api/v1/files/upload/ request without any authentication token/cookies and abuse a very long multipart form boundary to make the langflow app unusable for all users for an indefinite amount of time. This vulnerability is fixed in 1.0.19.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-qwqc-p3q8-wcg9 Langflow: Unauthenticated DoS through multipart form boundary file upload
History
Type Values Removed Values Added
First Time appeared Langflow
Langflow langflow
Vendors & Products Langflow
Langflow langflow
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.0.19, an attacker can send a /api/v1/files/upload/ request without any authentication token/cookies and abuse a very long multipart form boundary to make the langflow app unusable for all users for an indefinite amount of time. This vulnerability is fixed in 1.0.19.
Title Langflow: Unauthenticated DoS through multipart form boundary file upload
Weaknesses CWE-400
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 23, 2026, 5:56 PM
Reserved
Jun 16, 2026, 9:59 PM
Status
Analyzed
Published
Jun 23, 2026, 5:17 PM
Modified
Oct 25, 2026, 11:10 PM