CVE-2026-56278
Flowise - Session Hijacking via Weak Default Express Session Secret
- State
- Published
- Severity
- 9.3 Critical
- Published
- Jun 30, 2026
- Updated
- Jul 1, 2026
- Reserved
- Jun 20, 2026
Description
Flowise before 3.1.0 (affected versions 3.0.13 and earlier) uses a weak hardcoded default secret ('flowise') for the express-session middleware when the EXPRESS_SESSION_SECRET environment variable is not set (packages/server/src/enterprise/middleware/passport/index.ts). Because this default secret is publicly visible in the source code, an attacker can forge valid signed session cookies to impersonate any user and bypass authentication.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 9.3 Critical | 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 | VulnCheck |
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | VulnCheck |
Weaknesses
- CWE-798 Use of Hard-coded Credentials
Affected Products
| Product | Versions |
|---|---|
FlowiseFlowise |
|
References
- GitHub Security Advisory (GHSA-2qqc-p94c-hxwh)vendor-advisory
- VulnCheck Advisory: Flowise - Session Hijacking via Weak Default Express Session Secretthird-party-advisory
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