CVE-2026-77502 Microsoft CVE debrief

Who should care

Defenders responsible for Windows DHCP Server systems, including system administrators, network administrators, and cybersecurity teams, should prioritize patching to prevent potential denial-of-service attacks. This includes reviewing and updating incident response plans, monitoring network traffic for potential denial-of-service attacks, and ensuring that all necessary security measures are in place to protect

Why it matters

CVE-2026-77502 is a high-severity vulnerability in Windows DHCP Server that allows an unauthorized attacker to deny service over a network. Defenders should prioritize patching vulnerable systems to prevent potential denial-of-service attacks.

• Potential denial-of-service attacks
• Increased risk of network downtime
• Need for patching vulnerable systems
• Potential impact on business operations

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. This high-severity vulnerability, with a CVSS score of 7.5, requires immediate attention from defenders. Microsoft has released a patch, and defenders should prioritize patching vulnerable systems to prevent potential denial-of-service attacks. The CVE record and NVD entry provide details on the vulnerability, including its CVSS score and severity. Affected product deployments should be identified in managed environments, and an

Defensive priority

Patching vulnerable systems is a high priority to prevent potential denial-of-service attacks.

Recommended defensive actions

• Patch vulnerable systems
• Review and update incident response plans
• Monitor network traffic for potential denial-of-service attacks

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

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.