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PatchSiren cyber security CVE debrief

CVE-2026-78457 Microsoft CVE debrief

CVE-2026-78457 is a high-severity vulnerability in the Windows Security Health Service that allows an authorized attacker to elevate privileges locally. The vulnerability has a CVSS score of 7 and is classified as CWE-416. Microsoft has released a patch for this vulnerability. System administrators and security teams should review system configurations and monitor system logs for suspicious activity. The vulnerability is a use-after-free issue in the Windows Security Health Service. Affected product deployments should be confirmed in managed environments and assigned an owner for follow-up.

Vendor
Microsoft
Product
Windows 11 Version 24H2
CVSS
HIGH 7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-09-11
Advisory published
2026-09-08
Advisory updated
2026-09-11

Who should care

System administrators and security teams responsible for Windows systems, especially those with high privilege escalation risk, should apply patches immediately and review system configurations for potential exposure. They should also monitor system logs for suspicious activity and check relevant monitoring, detection, and logs for exposed assets that need extra review.

Why it matters

CVE-2026-78457 is a high-severity vulnerability in the Windows Security Health Service that allows an authorized attacker to elevate privileges locally. System administrators and security teams should apply patches immediately, review system configurations, and monitor system logs for suspicious activity.

  • Potential privilege escalation
  • Increased risk of system compromise

Technical summary

CVE-2026-78457 is a high-severity vulnerability in the Windows Security Health Service that allows an authorized attacker to elevate privileges locally. The vulnerability has a CVSS score of 7 and is classified as CWE-416. The vulnerability is a use-after-free issue in the Windows Security Health Service. Microsoft has provided a patch for this vulnerability. System administrators and security teams should apply patches immediately, especially for systems with high privilege escalation risk.

Defensive priority

Apply patches immediately, especially for systems with high privilege escalation risk

Recommended defensive actions

  • Apply patches immediately, especially for systems with high privilege escalation risk
  • Review system configurations for potential exposure
  • Monitor system logs for suspicious activity

Evidence notes

The vulnerability is described as a use-after-free issue in the Windows Security Health Service. Microsoft has provided a patch for this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-78457 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-78457

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

  • CVE-2026-78457 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-78457

    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.