Vulnerability · Published Jul 8, 2026 · Assigned by VulnCheck

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

Medium 6.8

In plain English

A medium-severity missing authentication in midscene from web-infra-dev. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.3%top 76.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
web-infra-dev	midscene	0 – through 1.10.3

Weakness: CWE-1385, CWE-306 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

References

Researcher Disclosure technical-description, exploit
Fix PR issue-tracking
Fix Commit patch
https://www.vulncheck.com/advisories/midscene-bridge-server-session-hijack-via-unauthenticated-websocket third-party-advisory