GHSA-2qqc-p94c-hxwh CVE-2026-56278
Flowise: Weak Default Express Session Secret
- Severity
- 9.3 / 10
- Critical · CVSS 4.0
- Exploit chance (EPSS)
- 0.53%
- Chance of exploitation in the next 30 days. Higher than 44.69% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-798 Use of Hard-coded Credentials
- Fix
3.1.0- Upgrade flowise to this version or later
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.
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| flowise | < 3.1.0 |
3.1.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
flowise npm → 3.1.0
- npm
npm install flowise@3.1.0- yarn
yarn add flowise@3.1.0- pnpm
pnpm add flowise@3.1.0
Severity breakdown
CVSS 4.0 9.3
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Not defined
- Scope
- X
CVSS 3.0 5.6
CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N
- Attack vector
- Local
- Attack complexity
- High
- Privileges required
- High
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Weakness
CWE-798: Use of Hard-coded Credentials
The product contains hard-coded credentials, such as a password or cryptographic key.
How to prevent it
- Architecture and Design: For outbound authentication: store passwords, keys, and other credentials outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible [REF-7]. In Windows environments, the Encrypted File System (EFS) may provide some protection.
- Architecture and Design: For inbound authentication: Rather than hard-code a default username and password, key, or other authentication credentials for first time logins, utilize a "first login" mode that requires the user to enter a unique strong password or key.
- Architecture and Design: If the product must contain hard-coded credentials or they cannot be removed, perform access control checks and limit which entities can access the feature that requires the hard-coded credentials. For example, a feature might only be enabled through the system console instead of through a network connection.
- Architecture and Design: For inbound authentication using passwords: apply strong one-way hashes to passwords and store those hashes in a configuration file or database with appropriate access control. That way, theft of the file/database still requires the attacker to try to crack the password. When handling an incoming password during authentication, take the hash of the password and compare it to the saved hash. Use randomly assigned salts for each separate hash that is generated. This increases the amount of computation that an attacker needs to conduct a brute-force attack, possibly limiting the effectiveness of the rainbow table method.
- Architecture and Design: For front-end to back-end connections: Three solutions are possible, although none are complete. The first suggestion involves the use of generated passwords or keys that are changed automatically and must be entered at given time intervals by a system administrator. These passwords will be held in memory and only be valid for the time intervals. Next, the passwords or keys should be limited at the back end to only performing actions valid for the front end, as opposed to having full access. Finally, the messages sent should be tagged and checksummed with time sensitive values so as to prevent replay-style attacks.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-w7x8-q2gp-5cgg Flowise Prompt Injection to RCE and SSRF via CSV/Airtable Agent Python Validator Bypass | Critical | Also affects flowise |
| GHSA-9gvv-qjj3-2p6g Flowise NodeVM sandbox escape via puppeteer allowlist - authenticated RCE and arbitrary file read via Chromium | High | Also affects flowise |
| GHSA-qgvm-j2hm-6m38 Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service | Critical | Also affects flowise |
| GHSA-5xvg-pmgg-3mxr Flowise: CSV Agent Prompt Injection Remote Code Execution Vulnerability | Critical | Also affects flowise |
| GHSA-gmmw-qg98-6j6p Flowise: Broken Access Control in Stripe Subscription Endpoints Allows Cross-Tenant Billing Manipulation | High | Also affects flowise |
| GHSA-8gj2-2cvc-6xx7 Flowise: Unauthenticated Credential Abuse via Text-to-Speech Endpoint Allows Unauthorized Use of Private Chatflow TTS Credentials | Medium | Also affects flowise |
| GHSA-fm2f-4339-4p2f Flowise: Missing Authorization on Execution Update Endpoint | Medium | Also affects flowise |
| GHSA-wch5-xp77-fxg4 Flowise: Cross-Workspace OAuth2 Credential Metadata Leak | High | Also affects flowise |
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor