CVE-2026-46544CWE-639

Microsoft UFO reuses client-supplied WebSocket session IDs and replays stale task results to new authenticated requesters

Medium · published May 27, 2026

CVSS v3.1
5.3
EPSS
1%
Percentile
51.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00672 · 51.5th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2026-05-27T21:53Z
EPSS history
Timeline
  • 27 MAY 21:53Z
    Microsoft UFO reuses client-supplied WebSocket session IDs and replays stale task results to new authenticated requesters
    cvelistv5