# CVE-2026-55446 — langflow-ai langflow

> As of 2026-06-23, CVE-2026-55446 is a HIGH-severity vulnerability in langflow-ai langflow, CVSS v3.1 7.5, EPSS 0.3% (23.3th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-55446 as of 2026-06-23; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-06-23

## What is CVE-2026-55446?

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.

The record classifies CVE-2026-55446 under weakness class [CWE-400](https://intel.threadlinqs.com/cwe/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:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 23.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-06-23

## Is CVE-2026-55446 being exploited?

It currently carries a trending score of 35 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [langflow-ai](https://intel.threadlinqs.com/vendors/langflow-ai): langflow

Affected software packages:

- `pip:langflow` — patched in 1.0.19

## How to fix CVE-2026-55446

The record marks a vendor fix as available for CVE-2026-55446. Fixed versions are recorded for 1 package: pip:langflow 1.0.19. Patch reference: [https://github.com/langflow-ai/langflow/pull/3923](https://github.com/langflow-ai/langflow/pull/3923). Vendor advisory: [https://github.com/langflow-ai/langflow/security/advisories/GHSA-qwqc-p3q8-wcg9](https://github.com/langflow-ai/langflow/security/advisories/GHSA-qwqc-p3q8-wcg9). 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-2026-55446

No threat campaign in the Threadlinqs corpus currently references CVE-2026-55446, 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 2026-06-26. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com](https://github.com/langflow-ai/langflow/security/advisories/GHSA-qwqc-p3q8-wcg9)

**Other references**

- [github.com](https://github.com/langflow-ai/langflow/pull/3923)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-55446
Full detection coverage and IOCs for threats exploiting CVE-2026-55446 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp