CVE-2026-56278
Flowise - Session Hijacking via Weak Default Express Session Secret
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.
INFO
Published Date :
June 30, 2026, 11:17 p.m.
Last Modified :
July 6, 2026, 3:27 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update Flowise to version 3.1.0 or later.
- Set a strong, unique EXPRESS_SESSION_SECRET environment variable.
- Restart the Flowise application after changes.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-56278.
| URL | Resource |
|---|---|
| https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-2qqc-p94c-hxwh | Mitigation Vendor Advisory |
| https://www.vulncheck.com/advisories/flowise-session-hijacking-via-weak-default-express-session-secret | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56278 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-56278
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-56278 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56278 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 06, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:* versions up to (excluding) 3.1.0 Added Reference Type VulnCheck: https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-2qqc-p94c-hxwh Types: Mitigation, Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/flowise-session-hijacking-via-weak-default-express-session-secret Types: Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 01, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-56278', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-01T13:46:50.524143Z'} -
New CVE Received by [email protected]
Jun. 30, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Flowise', 'product': 'Flowise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.0', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise', 'defaultStatus': 'unaffected'}] 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-798 Added Reference https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-2qqc-p94c-hxwh Added Reference https://www.vulncheck.com/advisories/flowise-session-hijacking-via-weak-default-express-session-secret