CVE-2026-56278 json
Flowise - Session Hijacking via Weak Default Express Session Secret
published 2026-04-16 6 mo ago modified 2026-07-08 4 mo ago also GHSA-2qqc-p94c-hxwh , EUVD-2026-40433
- cvss
- 9.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 44%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm flowise 3.1.0
- Flowise Flowise 3.1.0
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 4 mo ago
Exploit prediction
0.53% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | 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 |
| CNA | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| CNA | 4.0 | 9.3 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| GitHub | 3.0 | 5.6 | CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | flowise | <3.1.0 |
3.1.0 |
Affected products
- Flowise Flowise
Classification
- Weakness
-
- CWE-798 Use of Hard-coded Credentials
References
-
github.com
/FlowiseAI/Flowise/security/advisories/GHSA-2qqc-p94c-hxwh
vendor-advisory, web, mitigation
-
vulncheck.com
/advisories/flowise-session-hijacking-via-weak-default-express-session-secret
third-party-advisory
-
github.com
/FlowiseAI/Flowise
package
Sources
- CVE List CVE-2026-56278
- GitHub Advisory GHSA-2qqc-p94c-hxwh
- NVD CVE-2026-56278
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