Unauthenticated denial of service via out-of-bounds read
Published Sep 8, 2026 · Updated Sep 9, 2026
Out-of-bounds read in Windows DHCP Server allows remote attackers to crash affected Windows systems through network traffic. Microsoft identifies the DHCP Server component as reading beyond a buffer boundary but has not disclosed the affected parser, message field, or malformed input. No authentication or user interaction is required; successful exploitation interrupts DHCP service by crashing the affected system.
Summary
What happened
Out-of-bounds read in Windows DHCP Server allows remote attackers to crash affected Windows systems through network traffic. Microsoft identifies the DHCP Server component as reading beyond a buffer boundary but has not disclosed the affected parser, message field, or malformed input. No authentication or user interaction is required; successful exploitation interrupts DHCP service by crashing the affected system.
The record
- CVE
- CVE-2026-77886
- Published
- Sep 8, 2026
- Updated
- Sep 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-125, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
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=10.0.17763.0 <10.0.17763.9245
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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