CVE-2026-59804 HIGH

CVE-2026-59804: Midscene Bridge Server - Session Hijack via Unauthenticated WebSocket

Vendor Web-Infra-Dev
Product midscene
Weakness CWE-1385
Published July 8, 2026
Last update July 8, 2026

CVSS base score

7.6/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Midscene Bridge Server through 1.10.3, fixed in commit 86f4118, contains a missing authentication and CORS misconfiguration vulnerability that allows unauthenticated remote attackers to hijack active bridge sessions by opening a cross-origin WebSocket connection to the local Socket.IO server, which performs no Origin header validation and requires no authentication token. Attackers can connect from any web page visited by the victim to seize the single-client slot, intercept and inject automation commands, exfiltrate command-payload data, or unconditionally terminate the server by supplying the MIDSCENE_BRIDGE_SIGNAL_KILL query parameter.

Key dates

02Disclosure timeline

July 8, 2026 CVE published