The Node.js web service on VOS (previously Versa FlexVNF) is used for URL-based Zero Touch Provisioning (ZTP) of the VOS appliance and is not required after provisioning is complete. The express-session middleware in server.js is configured with a hardcoded secret that is identical across all VOS appliances and is used to sign session cookies. An attacker who obtains a valid session ID from any source can compute the correct HMAC-SHA256 signature and forge a session cookie that the server accepts as legitimate. Because the secret is shared across all VOS appliances, a forged cookie is accepted by any VOS appliance in the deployment.  Versa’s security hardening guide for Hubs, Branches, and Controllers recommends disabling the Node.js web service after the initial provisioning of the VOS device. This vulnerability is not exploitable on VOS devices where the Node.js web service has been disabled.
History

Tue, 10 Nov 2026 10:15:00 +0000

Type Values Removed Values Added
First Time appeared Versa
Versa vos
Vendors & Products Versa
Versa vos

Tue, 10 Nov 2026 09:15:00 +0000

Type Values Removed Values Added
Title Legacy Hard-Coded Session Secret in VOS Node.js Web Service Enables Cookie Forgery

Tue, 10 Nov 2026 00:45:00 +0000

Type Values Removed Values Added
Description The Node.js web service on VOS (previously Versa FlexVNF) is used for URL-based Zero Touch Provisioning (ZTP) of the VOS appliance and is not required after provisioning is complete. The express-session middleware in server.js is configured with a hardcoded secret that is identical across all VOS appliances and is used to sign session cookies. An attacker who obtains a valid session ID from any source can compute the correct HMAC-SHA256 signature and forge a session cookie that the server accepts as legitimate. Because the secret is shared across all VOS appliances, a forged cookie is accepted by any VOS appliance in the deployment.  Versa’s security hardening guide for Hubs, Branches, and Controllers recommends disabling the Node.js web service after the initial provisioning of the VOS device. This vulnerability is not exploitable on VOS devices where the Node.js web service has been disabled.
Weaknesses CWE-798
References
Metrics cvssV3_0

{'score': 7.6, 'vector': 'CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published: 2026-11-10T00:32:36.888Z

Updated: 2026-11-12T13:28:18.397Z

Reserved: 2026-10-07T15:00:00.550Z

Link: CVE-2026-107243

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-10T01:17:12.470

Modified: 2026-11-12T19:09:06.967

Link: CVE-2026-107243

cve-icon Redhat

No data.