Unauthenticated code execution via integer underflow
Published Jun 9, 2026 · Updated Jun 9, 2026
Integer underflow in Microsoft Windows Performance Monitor allows remote attackers to execute arbitrary code over a network. Microsoft has not disclosed which Performance Monitor routine underflows or how network input reaches the arithmetic operation. Exploitation requires no credentials or user interaction but has high attack complexity and grants code execution in the affected system context.
Summary
What happened
Integer underflow in Microsoft Windows Performance Monitor allows remote attackers to execute arbitrary code over a network. Microsoft has not disclosed which Performance Monitor routine underflows or how network input reaches the arithmetic operation. Exploitation requires no credentials or user interaction but has high attack complexity and grants code execution in the affected system context.
The record
- CVE
- CVE-2026-42981
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2025 (Server Core installation)
- Classifications
- CWE-191, T1210
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.26100.0 <10.0.26100.32995
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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