SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-105791

Prior to 3.0.9, the run_shell tool in the CommandLineExecutor component of ufo/client/mcp/local_servers/cli_mcp_server.py validates only the first token of the bash_command parameter and permits explorer.exe.

HIGH 7.5EPSS 0.73%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.73%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Microsoft UFO is an open-source framework for intelligent automation across devices and platforms. Prior to 3.0.9, the run_shell tool in the CommandLineExecutor component of ufo/client/mcp/local_servers/cli_mcp_server.py validates only the first token of the bash_command parameter and permits explorer.exe. On Windows, explorer.exe delegates its following path argument to ShellExecute, so an attacker-influenced agent call can launch an arbitrary executable or script as the desktop user even though the subprocess uses shell=False. Exploitation depends on a user running an affected agent workflow and on inducing the tool call, but successful execution can access or modify that user's files, tokens, and sessions. This issue is fixed in version 3.0.9.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
0.73% probability · 54th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-88, CWE-184
Source
security-advisories@github.com
EPSS trend
0%3%5%7 October 2026: 0.62%27 October 2026: 0.73%7 October 202627 October 2026

EPSS moved from 0.6% on 7 October 2026 to 0.7% on 27 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.