Vulnerability · Published May 27, 2026 · Assigned by GitHub_M
CVE-2026-46416Microsoft UFO shared WebSocket handler state causes cross-client response hijacking
Medium 6.3
In plain English
A medium-severity improper access control in UFO from microsoft. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities).
Official description
Microsoft UFO open-source framework for intelligent automation across devices and platforms. In 3.0.1-4-ge2626659, Microsoft UFO creates one shared UFOWebSocketHandler instance and reuses it for multiple authenticated WebSocket connections. The handler stores per-connection protocol objects in mutable instance fields. Each new WebSocket connection overwrites those fields. Later, message handlers send responses through the shared fields instead of through protocol objects bound to the originating connection. As a result, the most recently connected authenticated client can receive protocol responses that belong to another authenticated client.
Affected products (as reported)
Weakness: CWE-284, CWE-488 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
References
- https://github.com/microsoft/UFO/security/advisories/GHSA-cwwh-p9rv-4pj4 x_refsource_CONFIRM