by Kastro
Paper/Archive/CVE-2026-56278

CVE-2026-56278

Flowise Flowise — Flowise - Session Hijacking via Weak Default Express Session Secret

EPSS 0.5%CVSS 9.3
critical.is priorityof 100
37
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 44.7.447 × 208.9No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
Flowise< 3.1.03.1.0CNA

Scores by source

VulnCheck (CNA)9.3CVSS: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 (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

advisorygithub.com/FlowiseAI/Flowise/security/advisories/GHSA-2qqc-p94c-hxwhwriteupvulncheck.com/advisories/flowise-session-hijacking-via-weak-default-express-session-secret