# CVE-2026-16791: Lenovo XClarity Essentials OneCLI temporary file overwrite

Source: https://junglewise.ai/threats/cve-2026-16791-lenovo-xclarity-essentials-onecli-temporary-file-overwrite  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-04. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-16791 · Severity: low · CVSS 3.9 · Published 2026-08-04

XClarity Essentials OneCLI is a systems management tool for Linux used to configure and manage Lenovo servers. A flaw in temporary file handling allows a low-privileged local attacker to overwrite or truncate arbitrary files when the tool runs with elevated privileges, potentially corrupting critical system or application files.

Technologies: [Lenovo XClarity Essentials OneCLI](https://junglewise.ai/threats/technologies/xclarity-essentials-onecli). Vendors: [Lenovo](https://junglewise.ai/threats/vendors/lenovo).

## Quick answers

**Is CVE-2026-16791 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-16791 being exploited in the wild.

**How severe is CVE-2026-16791?** Low severity, with a CVSS score of 3.9, published 4 August 2026.

**Which products and versions are affected?** Lenovo XClarity Essentials OneCLI 5.5.0 and below.

**Is there a fix for CVE-2026-16791?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-16791 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2026-16791?** Check whether you run Lenovo XClarity Essentials OneCLI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This is a temporary file creation vulnerability (insecure tempfile handling) in the Linux version of XClarity Essentials OneCLI 5.5.0 and earlier. The vulnerable component creates temporary files in a manner that allows predictable naming or locations, enabling a local low-privileged attacker to exploit a time-of-check-time-of-use (TOCTOU) race condition. When OneCLI is executed with elevated privileges, an attacker can overwrite or truncate arbitrary local files with program-generated data. The attack requires local access and execution context on the affected system, but does not require authentication. Mitigation involves upgrading to a patched version above 5.5.0.

## Affected products

- Lenovo XClarity Essentials OneCLI 5.5.0 and below

## Timeline

- 2026-08-04: disclosed

## References

- [https://support.lenovo.com/us/en/solutions/ht116433](https://support.lenovo.com/us/en/solutions/ht116433)

## Related threats

- [Lenovo XClarity Essentials OneCLI command injection in SSH operation](https://junglewise.ai/threats/cve-2026-65952-improper-neutralization-of-special-elements-used-in-an-os-command)
- [Lenovo XClarity Essentials OneCLI path traversal in TAR.GZ extraction](https://junglewise.ai/threats/cve-2026-65951-a-path-traversal-vulnerability-in-the-tar-gz-extraction-logic-of)
- [Lenovo XClarity Essentials OneCLI path traversal in ZIP extraction](https://junglewise.ai/threats/cve-2026-65950-a-path-traversal-vulnerability-in-the-zip-extraction-logic-of)