CVE-2026-59804

MEDIUM 6.8

Midscene Bridge Server - Session Hijack via Unauthenticated WebSocket

CVSS Score

6.8

EPSS Score

0.2%

EPSS Percentile

12th

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.

CWE	CWE-1385 CWE-306
Vendor	web-infra-dev
Product	midscene
Published	Jul 8, 2026
Last Updated	Jul 9, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Affected Versions

web-infra-dev / midscene

0 ≤ 1.10.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/web-infra-dev/midscene/issues/2752 github.com: https://github.com/web-infra-dev/midscene/pull/2759 github.com: https://github.com/web-infra-dev/midscene/commit/86f4118d1d847041c63d79e347e08c87c3f1a882 vulncheck.com: https://www.vulncheck.com/advisories/midscene-bridge-server-session-hijack-via-unauthenticated-websocket

Credits

George Chen