What is CVE-2026-55450?
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, unauthenticated users can upload any amount of data to the server without any limitations. No need for any prior knowledge, only network access to Langflow. This can lead to space exhaustion on the server. In addition, in the response, the absolute path of the uploaded file is reported to the attacker, which is an information leak that can assist in chaining other primitives. This vulnerability is fixed in 1.9.1.
The record classifies CVE-2026-55450 under weakness classes CWE-200, CWE-306, CWE-400. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 104 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.3 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H - EPSS (FIRST)
- 0.3% probability of exploitation in the next 30 days, higher than 22.6% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 5.6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-06-23
Is CVE-2026-55450 being exploited?
It currently carries a trending score of 35 in the Threadlinqs vulnerability feed.
Affected products and versions
- langflow-ai: langflow
Affected software packages:
pip:langflow— patched in 1.9.1
How to fix CVE-2026-55450
The record marks a vendor fix as available for CVE-2026-55450. Fixed versions are recorded for 1 package: pip:langflow 1.9.1. Patch reference: https://github.com/langflow-ai/langflow/pull/12831. Vendor advisory: https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-55450
No threat campaign in the Threadlinqs corpus currently references CVE-2026-55450, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.