CVE-2026-56278

Flowise - Session Hijacking via Weak Default Express Session Secret

Published Jun 30, 2026 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Flowise - Session Hijacking via Weak Default Express Session Secret
First Time appeared Flowiseai
Flowiseai flowise
Weaknesses CWE-798
CPEs cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:*
Vendors & Products Flowiseai
Flowiseai flowise
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 9.3, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Jul 1, 2026, 2:28 PM
Reserved
Jun 20, 2026, 1:51 AM
Status
Analyzed
Published
Jun 30, 2026, 11:17 PM
Modified
Jul 6, 2026, 3:27 PM