# CVE-2026-42981: Microsoft Windows Performance Monitor integer underflow remote code execution

Source: https://junglewise.ai/threats/cve-2026-42981-microsoft-windows-performance-monitor-integer-underflow-remote  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-09. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-42981 · Severity: high · CVSS 8.1 · Published 2026-06-09

A vulnerability exists in Windows Performance Monitor, a tool used to track and analyze system resource usage. An unauthorized attacker could exploit this flaw over a network to run malicious code on a target system. This could lead to a complete compromise of the affected machine, potentially resulting in data theft or service disruption.

Technologies: [Microsoft Windows Performance Monitor](https://junglewise.ai/threats/technologies/windows-performance-monitor). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-42981 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42981 being exploited in the wild.

**How severe is CVE-2026-42981?** High severity, with a CVSS score of 8.1, published 9 June 2026.

**Which products and versions are affected?** Microsoft Windows Performance Monitor.

**Is there a fix for CVE-2026-42981?** 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-2026-42981 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-42981?** Check whether you run Microsoft Windows Performance Monitor. 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

An integer underflow (CWE-191) vulnerability exists in the Windows Performance Monitor component. The flaw is triggered when the application fails to properly validate input data, leading to a wrap or wraparound condition during memory allocation or buffer management. An unauthenticated attacker can exploit this over the network to achieve remote code execution. While the attack vector is network-based, the CVSS score reflects a high attack complexity, suggesting specific environmental conditions or timing may be required for successful exploitation. Microsoft has released security updates to address this issue.

## Affected products

- Microsoft Windows Performance Monitor

## Timeline

- 2026-06-09: disclosed
- 2026-06-09: advisory

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42981](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42981)

## Related threats

- [Microsoft Windows Performance Monitor privilege escalation](https://junglewise.ai/threats/cve-2026-85333-concurrent-execution-using-shared-resource-with-improper)
- [Microsoft Windows Performance Monitor integer underflow remote code execution](https://junglewise.ai/threats/cve-2026-42974-microsoft-windows-performance-monitor-integer-underflow-remote)