Vulnerability · Published Jul 16, 2026 · Assigned by GitHub_M

CVE-2026-55440Microsoft UFO: COMMAND_RESULTS handler creates unowned sessions, allowing authenticated session-squatting denial of service

Medium 6.5

In plain English

A medium-severity uncontrolled resource consumption in UFO from microsoft. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.7%top 45.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
microsoft	UFO	< 3.0.7

Weakness: CWE-400, CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/microsoft/UFO/security/advisories/GHSA-hxjv-fmjf-wmjf x_refsource_CONFIRM
https://github.com/microsoft/UFO/commit/cc653bde75337ab60c320e6b7cb61b86ba6ca948 x_refsource_MISC
https://github.com/microsoft/UFO/releases/tag/3.0.7 x_refsource_MISC