Unauthenticated unrestricted file upload in Langflow leading to DoS and path disclosure
CVE-2026-55450 affects Langflow versions prior to 1.9.1. The vulnerability is present in the deprecated POST /api/v1/upload/{flow_id} endpoint, which did not enforce authentication and did not validate the flow_id parameter. As a result, any remote unauthenticated user with network access to a Langflow instance could upload arbitrary amounts of data to the server. Because the endpoint lacked effective upload limits, an attacker could repeatedly submit files until server storage was exhausted. The endpoint response also disclosed the absolute filesystem path of the uploaded file, creating an information leak about the server’s directory layout that could support chained exploitation.
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Impact
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Mitigation
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Remediation
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Exploits
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Affected products & vendors
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Recent activity
5 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An unauthenticated file upload vulnerability in Langflow that can cause denial of service through disk space exhaustion and leak the absolute path of uploaded files.
A critical unauthenticated file upload vulnerability in Langflow that allows remote attackers to upload unlimited data, causing denial of service through disk space exhaustion and leaking the server's absolute file path in the JSON response.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.