Langflow Authorization Bypass Through User-Controlled Key Vulnerability
CVE-2026-55255
How serious is it
- Severity: not rated yet.
- Exploit prediction (EPSS): 0.9% chance of exploitation in the next 30 days, higher than 59% of all vulnerabilities.
- Confirmed exploited in the wild (CISA KEV).
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-55255?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Langflow Langflow
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
Langflow contains an authorization bypass through user-controlled key vulnerability which allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- No references listed.
Merged from CISA KEV, FIRST EPSS. Last updated 23 Oct 2026. All vulnerabilities · RSS · JSON