Local privilege escalation via out-of-bounds read
Published Sep 8, 2026 · Updated Sep 9, 2026
Out-of-bounds read in Microsoft Trace Data Helper on affected Windows 11 and Server 2025 builds allows local users to elevate privileges. Microsoft has not disclosed which Trace Data Helper routine performs the out-of-bounds read or how attacker-controlled input reaches it. Low-privileged local access is required; successful exploitation elevates privileges within the affected host without user interaction.
Summary
What happened
Out-of-bounds read in Microsoft Trace Data Helper on affected Windows 11 and Server 2025 builds allows local users to elevate privileges. Microsoft has not disclosed which Trace Data Helper routine performs the out-of-bounds read or how attacker-controlled input reaches it. Low-privileged local access is required; successful exploitation elevates privileges within the affected host without user interaction.
The record
- CVE
- CVE-2026-56198
- Published
- Sep 8, 2026
- Updated
- Sep 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2025 (Server Core installation)
- Classifications
- CWE-125, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 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 <10.0.26100.33438
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.
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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