Langflow: Unauthenticated Flow Execution via Webhook Authentication Bypass

langflow (pip)

### Summary A vulnerability in Langflow's webhook authentication logic allows unauthenticated users to trigger the execution of any flow. The system incorrectly bypasses API key validation when the `WEBHOOK_AUTH_ENABLE` configuration is set to `False`. This allows a remote attacker who knows a flow's UUID to execute it as if they were the owner,…

First seen: 5 Oct 2026
Last update: 5 Oct 2026, 22:31 UTC
Fixed in: langflow 1.9.1
Identifiers: CVE-2026-8505
CVSS: 9.8
Source: GitHub advisory
On the menu as: PyPI packages
LLM gateways

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Langflow: Unauthenticated Flow Execution via Webhook Authentication Bypass
Severity: critical. Patch status: patched.
Affected: langflow (pip)
Fixed in: langflow 1.9.1
Ids: CVE-2026-8505

### Summary A vulnerability in Langflow's webhook authentication logic allows unauthenticated users to trigger the execution of any flow. The system incorrectly bypasses API key validation when the `WEBHOOK_AUTH_ENABLE` configuration is set to `False`. This allows a remote attacker who knows a flow's UUID to execute it as if they were the owner,…

## Steps
1. Search every lockfile and manifest (package-lock.json, yarn.lock, pnpm-lock.yaml, requirements*.txt, poetry.lock, uv.lock, composer.lock, go.sum, Cargo.lock, Gemfile.lock) for `langflow`. For each hit, compare the installed version with the fix on the same major line: langflow 1.9.1. If it's lower, give the exact upgrade command for the package manager this repo uses.
2. This incident involves a provider (ai-gateways). Search config, CI and env templates (.env.example, wrangler.toml, vercel.json, terraform, workflow secrets) for credentials stored there. List each secret by name, where it is used, and how to rotate it. Never print secret values.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-8505") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://github.com/advisories/GHSA-cf6m-vc3m-7cgm https://github.com/langflow-ai/langflow/commit/cb6f7508dda83ead9c3e4417e96e4b5bd9a260c3 https://github.com/langflow-ai/langflow/pull/12845 https://github.com/langflow-ai/langflow/security/advisories/GHSA-cf6m-vc3m-7cgm https://nvd.nist.gov/vuln/detail/CVE-2026-8505
https://pwned.coffee/i/langflow-unauthenticated-flow-execution-via-webhook-auth-cve-2026-8505

Sources

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