---
id: "CVE-2026-90991"
kind: "vulnerability"
aliases: ["CVE-2026-90991"]
title: "Langflow: authenticated users can exhaust resources and cause denial of service"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: [{"name": "Langflow OSS", "fixed": ["1.12.5"], "affected": ">= 1.0.0, <= 1.12.4", "ecosystem": "vendor"}]
ecosystems: []
tags: ["ai-tooling", "langflow", "self-hosted"]
not_affected_if: ["no-authenticated-user-exposure", "version-outside-range"]
published_at: "2026-10-29T16:20:05+00:00"
first_seen_at: "2026-10-29T16:26:03+00:00"
updated_at: "2026-10-29T16:32:37+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90991", "first_seen_at": "2026-10-29T16:26:03+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-29T16:32:37+00:00"}]
---

# Langflow: authenticated users can exhaust resources and cause denial of service

IBM Langflow OSS versions 1.0.0 through 1.12.4 allow a logged-in remote user to trigger unlimited resource allocation. An attacker can use this to make the service unavailable.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Langflow OSS affected >= 1.0.0, <= 1.12.4 fixed 1.12.5

## How to check

- Check the installed Langflow version with `langflow --version` or the package manager, and compare it against the affected range `1.0.0` to `1.12.4`.
- Confirm whether the Langflow instance is reachable from untrusted networks and whether accounts can be created or obtained by outsiders.

## Fix

Upgrade Langflow OSS to 1.12.5 (IBM: back up the installation, follow the Prepare to upgrade steps, test flows).

## Timeline

- 2026-10-29T16:26:03+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-90991
- 2026-10-29T16:32:37+00:00 analyst — IBM bulletin (19 Oct 2026) lists CVE-2026-90991 (CWE-770, CVSS 6.5, auth required) affecting Langflow OSS 1.0.0-1.12.4, fixed in 1.12.5. Bulletin does not name the endpoint; no workaround for this CVE (MCP stdio controls are for other CVEs). No exploitation or PoC found.

## Documents

- [advisory] IBM Security Bulletin: Langflow OSS is affected by multiple vulnerabilities (1.12.5) https://www.ibm.com/support/pages/security-bulletin-langflow-oss-affected-multiple-vulnerabilities-1

## From the sources

IBM Langflow OSS 1.0.0 through 1.12.4 could allow a remote authenticated attacker to cause a denial of service due to allocation of resources without limits or throttling.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_