CVE-2026-46440

Detection Method: Kolega.dev Deep Code Scan

Description

The checkBasicAuth endpoint validates credentials in plaintext without rate limiting and with direct comparison.

Affected Code

public async checkBasicAuth(req: Request, res: Response) {
    const { username, password } = req.body
    if (username === process.env.FLOWISE_USERNAME && password === process.env.FLOWISE_PASSWORD) {
        return res.json({ message: 'Authentication successful' })

Evidence

Credentials are sent in plaintext in request body and compared directly without hashing. No rate limiting prevents brute force attacks. The endpoint returns different messages for success/failure, enabling enumeration.

Notes

The checkBasicAuth endpoint at line 128-135 has multiple security issues: (1) No rate limiting - the RateLimiterManager only applies to chatflow-specific endpoints, not auth endpoints. Attackers can perform unlimited brute force attempts. (2) Uses JavaScript === operator for comparison which is not constant-time, potentially enabling timing attacks. (3) Returns different messages for success ('Authentication successful') vs failure ('Authentication failed'), enabling credential enumeration. The endpoint compares plaintext credentials against environment variables FLOWISE_USERNAME and FLOWISE_PASSWORD. While this is basic auth for simpler deployments, the lack of rate limiting makes it actively exploitable for credential brute-forcing.

Credential brute-forcing - attackers can attempt unlimited username/password combinations against the basic auth system. Successful attacks grant access to the application.

CVE-2026-46440 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.1.2); upgrading removes the vulnerable code path.

Kodem intelligence

1. Implement rate limiting on this endpoint, 2) Use constant-time comparison to prevent timing attacks, 3) Consider using hashed comparison, 4) Return generic error messages, 5) Add logging for failed attempts.

1. What is CVE-2026-46440? CVE-2026-46440 is a high-severity security vulnerability in flowise (npm), affecting versions <= 3.1.1. It is fixed in 3.1.2.
2. How severe is CVE-2026-46440? CVE-2026-46440 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of flowise are affected by CVE-2026-46440? flowise (npm) versions <= 3.1.1 is affected.
4. Is there a fix for CVE-2026-46440? Yes. CVE-2026-46440 is fixed in 3.1.2. Upgrade to this version or later.
5. Is CVE-2026-46440 exploitable, and should I be worried? Whether CVE-2026-46440 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-46440 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-46440? Upgrade flowise to 3.1.2 or later.