CVE-2026-56278 | Flowise before 3.1.0 (affected versions 3.0.13 and earlier) … | CVSS 9.1 CRITICAL

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.

Metadata

CVE ID: CVE-2026-56278
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-20 01:51 UTC
Published: 2026-06-30 22:08 UTC
Last updated: 2026-07-01 14:28 UTC
Primary CWE: CWE-798
Use of Hard-coded Credentials
Vendor / Product: Flowise / Flowise
Sources: cve.org · NVD

Severity & Metrics

9.1 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

SSVC — CISA Coordinator

Exploitation: none
Automatable: yes
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
Flowise	Flowise	—	0 < 3.1.0, 3.1.0

Weakness (CWE)

CWE	Source	Description
CWE-798	cna	Use of Hard-coded Credentials

CVSS scores (2)

Score	Severity	Version	Source	Vector
9.3	CRITICAL	4.0	cna	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
9.1	CRITICAL	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References (2)

GitHub Security Advisory (GHSA-2qqc-p94c-hxwh) https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-2qqc-p94c-hxwh
VulnCheck Advisory: Flowise - Session Hijacking via Weak Default Express Session Secret https://www.vulncheck.com/advisories/flowise-session-hijacking-via-weak-default-express-session-secret