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Flowise: Weak Default Express Session Secret

Moderate severity GitHub Reviewed Published Apr 15, 2026 in FlowiseAI/Flowise • Updated Apr 16, 2026

Package

npm flowise (npm)

Affected versions

<= 3.0.13

Patched versions

3.1.0

Description

Detection Method: Kolega.dev Deep Code Scan

Attribute Value
Location packages/server/src/enterprise/middleware/passport/index.ts:55
Practical Exploitability High
Developer Approver faizan@kolega.ai

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.

References

@igor-magun-wd igor-magun-wd published to FlowiseAI/Flowise Apr 15, 2026
Published to the GitHub Advisory Database Apr 16, 2026
Reviewed Apr 16, 2026
Last updated Apr 16, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
High
Privileges required
High
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N

EPSS score

Weaknesses

Use of Hard-coded Credentials

The product contains hard-coded credentials, such as a password or cryptographic key. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-2qqc-p94c-hxwh

Source code

Credits

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