CVE-2026-66420

MeshCentral 1.1.21 contains a cross-site WebSocket hijacking protection bypass vulnerability that allows unauthenticated remote attackers to hijack authenticated administrator sessions by exploiting an unconditional early return in the CheckWebServerOriginName() function within webserver.js when self-signed certificates are in use. Attackers can open cross-origin WebSocket connections to any of the twelve WebSocket endpoints, send crafted action commands to exfiltrate the server sessionKey used to sign session cookies, forge session tokens as arbitrary users, and gain full remote control of all managed devices governed by the MeshCentral instance.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/Ylianst/MeshCentral
https://github.com/Ylianst/MeshCentral/commit/f04c9f4
https://github.com/Ylianst/MeshCentral/pull/7882
https://www.vulncheck.com/advisories/meshcentral-cross-site-websocket-hijacking-via-origin-validation-bypass-on-self-signed-certificate-deployments

Configurations

No configuration.

History

No history.

Information

Published : 2026-07-30 23:16

Updated : 2026-09-09 20:26

NVD link : CVE-2026-66420

Mitre link : CVE-2026-66420

CVE.ORG link : CVE-2026-66420

JSON object : View

Products Affected

No product.

CWE

CWE-346

Origin Validation Error

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