CVE-2026-46440 affects Flowise, the drag and drop builder for large language model flows. Before version 3.1.2, the checkBasicAuth endpoint compares credentials directly, as plaintext, with no rate limiting. The NVD record scores it CVSS 9.1 (critical), and the advisory rates it high. Upgrade to 3.1.2 or later.
What's affected
The NVD record says Flowise versions before 3.1.2 are affected, and the GitHub advisory lists the npm package flowise at 3.1.1 and earlier. The patched version is 3.1.2.
The advisory describes the endpoint comparing submitted credentials against the FLOWISE_USERNAME and FLOWISE_PASSWORD environment variables. It notes that different success and failure messages can help enumeration, and that the comparison is not constant time. The advisory's own CVSS score is 7.5 (High); the NVD score is 9.1.
How to check if you're exposed
- Find your Flowise version. For an npm install, run this in the install directory:
npm ls flowise
- For Docker, check the image tag you run and compare it with 3.1.2.
- If you use basic auth through the username and password environment variables, treat the instance as in scope.
- Check whether the instance is reachable from the internet.
What to do now
- Upgrade Flowise to 3.1.2 or later.
- Put Flowise behind a VPN, an identity aware proxy or an allowlist so the login endpoint is not open to the world.
- Change the Flowise username and password after upgrading, since unlimited guessing was possible before.
- Check access logs for bursts of failed attempts against the auth endpoint.
- Add rate limiting at your reverse proxy as a second layer.
Why it matters
The class is CWE-522, insufficiently protected credentials. With no limit on attempts, a short or common password can fall to guessing. Flowise often holds API keys for model providers and data sources, so access has real consequences.
The record's KEV flag is false, and the advisory does not report exploitation.
Quick check
Does a strong password remove the risk?
It lowers the chance that guessing works, but the advisory's remedy is the upgrade. Keep the instance off the open internet as well.
Sources
Last reviewed: 19 October 2026.
