CVE-2026-56278: Flowiseai Flowise

Critical severity, CVSS 9.1. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Flowiseai Flowise: before 3.1.0 (fixed in 3.1.0)

Published 2026-06-30. Last modified 2026-07-06.