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PatchSiren cyber security CVE debrief

CVE-2026-77893 Microsoft CVE debrief

CVE-2026-77893 is a high-severity vulnerability in Windows DHCP Server that allows an unauthorized attacker to deny service over a network. The vulnerability has a CVSS score of 7.5 and is classified as HIGH. Microsoft has released a patch for this vulnerability, and defenders should prioritize patching to prevent potential service disruptions. Affected product deployments should be confirmed in managed environments, and owners should be assigned for follow-up. The CVE record and NVD entry provide details on the vulnerability, including its CVSS score and severity.

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-09-16
Advisory published
2026-09-08
Advisory updated
2026-09-16

Who should care

Defenders responsible for Windows DHCP Server systems should prioritize patching to prevent potential service disruptions. This includes operators, platform administrators, vulnerability management teams, and security teams who need to review and update inventory to ensure affected systems are identified and patched. Compensating controls should be reviewed for exposed systems while remediation is scheduled and logs

Why it matters

CVE-2026-77893 is a high-severity vulnerability in Windows DHCP Server that allows an unauthorized attacker to deny service over a network. Defenders should prioritize patching to prevent potential service disruptions.

  • Potential service disruptions due to denial of service attacks
  • Need to verify affected systems and apply patches

Technical summary

The vulnerability is an out-of-bounds read in Windows DHCP Server, which allows an unauthorized attacker to deny service over a network. The CVE record and NVD entry provide details on the vulnerability, including its CVSS score and severity. Defenders should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. The vulnerability affects Windows DHCP Server systems, and defenders should plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Defensive priority

Patching is recommended to prevent potential service disruptions.

Recommended defensive actions

  • Apply patches released by Microsoft to prevent potential service disruptions
  • Review and update inventory to ensure affected systems are identified and patched
  • Monitor system logs for potential exploitation attempts

Evidence notes

The vulnerability is described as an out-of-bounds read in Windows DHCP Server, which allows an unauthorized attacker to deny service over a network. The CVE record and NVD entry provide details on the vulnerability, including its CVSS score and severity.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-77893 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-77893

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-77893 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-77893

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.