Vulnerability Database

353,823

Total vulnerabilities in the database

Flowise: Weak Default Express Session Secret — flowise

Use of Hard-coded Credentials

Detection Method: Kolega.dev Deep Code Scan

| Attribute | Value | |---|---| | Location | packages/server/src/enterprise/middleware/passport/index.ts:55 | | Practical Exploitability | High | | Developer Approver | [email protected] |

Description

Express session secret has a weak default value 'flowise' when EXPRESS_SESSION_SECRET is not set.

Affected Code

secret: process.env.EXPRESS_SESSION_SECRET || 'flowise'

Evidence

The default session secret 'flowise' is publicly visible and weak. Session cookies signed with this secret can be forged by attackers.

Impact

Session hijacking and forgery - attackers can create arbitrary session cookies to impersonate any user, bypassing all authentication mechanisms.

Recommendation

Require EXPRESS_SESSION_SECRET to be set with a strong random value. Throw an error on startup if not configured. Use cryptographically strong random strings (minimum 256 bits).

Notes

The Express session secret defaults to the string 'flowise' when EXPRESS_SESSION_SECRET is not set (line 55). This secret is used to sign session cookies via express-session middleware. Since 'flowise' is publicly visible in the source code, an attacker can forge valid session cookies to impersonate any user without authentication. The .env.example file has this commented out (# EXPRESS_SESSION_SECRET=flowise), implying it's optional, which compounds the risk. Unlike development-only defaults, this code path is active in production if the environment variable is not set. The application should require EXPRESS_SESSION_SECRET to be explicitly configured with a cryptographically strong random value and fail to start otherwise.

  • Published: Apr 16, 2026
  • Updated: Apr 17, 2026
  • GHSA: GHSA-2qqc-p94c-hxwh
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Medium
  • Score: 5.6
  • AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N

CWEs:

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.