CVE-2026-55440CWE-400CWE-862

Microsoft UFO: COMMAND_RESULTS handler creates unowned sessions, allowing authenticated session-squatting denial of service

Medium · published July 16, 2026

CVSS v3.1
6.5
EPSS
1%
Percentile
69.4
In the wild
Unconfirmed
What it is

Microsoft UFO open-source framework for intelligent automation across devices and platforms. Prior to 3.0.7, the COMMAND_RESULTS handler in ufo/server/ws/handler.py called get_or_create_session in ufo/server/services/session_manager.py without owner_client_id, allowing an authenticated client to create an unowned attacker-chosen session_id such as constellation_task_id = f"{task_name}@{task_id}" and deny the legitimate owner or exhaust memory with phantom sessions. This issue is fixed in version 3.0.7.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.01260 · 69.4th percentile
Weaknesses
CWE-400 · Uncontrolled Resource Consumption; CWE-862 · Missing Authorization
Published
2026-07-16T15:35Z
EPSS history
Timeline
  • 16 JUL 15:35Z
    Microsoft UFO: COMMAND_RESULTS handler creates unowned sessions, allowing authenticated session-squatting denial of service
    cvelistv5