CVE-2026-46538

Deferred Deferred - Pending Action

Microsoft UFO Constellation Task-Result Injection

Publication date: 2026-05-27

Last updated on: 2026-05-28

Assigner: GitHub, Inc.

Description

Microsoft UFO open-source framework for intelligent automation across devices and platforms. In 3.0.1-4-ge2626659, Microsoft UFO's constellation client tracks pending task responses by session_id only and does not verify that a TASK_END message came from the device that originally received the task. When the constellation sends a task to a target device, it records a pending Future under a session key. The pending task record stores the expected device ID, but the completion path ignores that binding. If another authenticated peer device sends a forged TASK_END with the same session_id, the constellation accepts the response and completes the victim device's pending Future with attacker-controlled result data. This is an authenticated cross-device task-result injection issue.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-05-27

Last Modified

2026-05-28

Generated

2026-07-07

AI Q&A

2026-05-28

EPSS Evaluated

2026-07-06

NVD

CVE-2026-46538

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	ufo	From 3.0.1 (inc) to 4-ge2626659 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-294	A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).
CWE-345	The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Microsoft UFO open-source framework for intelligent automation. Specifically, in version 3.0.1-4-ge2626659, the constellation client tracks pending task responses by session_id only and does not verify that a TASK_END message actually comes from the device that originally received the task.

When a task is sent to a target device, the system records a pending task under a session key and stores the expected device ID. However, when the task is completed, the system ignores the device ID binding and accepts a TASK_END message from any authenticated peer device with the same session_id.

This allows an attacker controlling another authenticated device to send a forged TASK_END message with the same session_id, causing the system to accept the attacker's result data as if it came from the original device. This is an authenticated cross-device task-result injection vulnerability.

Impact Analysis

This vulnerability can impact you by allowing an attacker with access to an authenticated device to inject false task completion results into the system.

Because the system accepts forged TASK_END messages from other devices, an attacker can manipulate task outcomes, potentially causing incorrect automation behavior or data corruption.

The CVSS score indicates a moderate severity with a base score of 5.9, highlighting that while the attack requires some privileges, it can lead to integrity loss and partial availability impact.

Compliance Impact

This vulnerability allows an authenticated attacker to inject forged task completion results from a different device, potentially leading to integrity issues in task processing.

While the CVE description does not explicitly mention compliance impacts, the integrity compromise could affect regulatory requirements related to data integrity and system reliability under standards such as GDPR and HIPAA.

However, since there is no direct information provided about compliance implications or data exposure, the exact effect on compliance with GDPR, HIPAA, or similar regulations cannot be determined from the given information.

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