Vulnerability · Published May 27, 2026 · Assigned by GitHub_M
CVE-2026-46544Microsoft UFO reuses client-supplied WebSocket session IDs and replays stale task results to new authenticated requesters
Medium 5.3
In plain English
A medium-severity authorization bypass via user-controlled key in UFO from microsoft. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% 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 accepts client-supplied session_id values in WebSocket task messages and reuses an existing in-memory session object if that session_id already exists. If a prior session has completed and remains in memory with populated results, a different authenticated client can send a new TASK message using the same session_id. The server re-enters the existing session object and sends the stale stored result to the new requester through the normal send_task_end() callback path. This is an authenticated cross-client stale result replay issue. The issue requires that the attacker knows or can predict a live or recently completed session_id.
Affected products (as reported)
Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
References
- https://github.com/microsoft/UFO/security/advisories/GHSA-29gc-vqjp-7fqf x_refsource_CONFIRM