CVE-2026-105791 json
Microsoft UFO: Arbitrary code execution in `run_shell` via `explorer.exe` argument injection
published last mo. modified last mo. also EUVD-2026-93419
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 54%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Is CVE-2026-105791 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- last mo.
Exploit prediction
0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- github.com https://github.com/microsoft/UFO/security/advisories/GHSA-cmq9-vqjf-4q2q referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
Affected products
- microsoft UFO
Classification
References
Sources
- CVE List CVE-2026-105791
- NVD CVE-2026-105791
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