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CVE-2026-45604 Microsoft CVE debrief

CVE-2026-45604 is a MEDIUM severity vulnerability with a CVSS score of 5.5. It is an out-of-bounds read issue in the Windows Application Identity (AppID) Subsystem that allows an authorized attacker to disclose information locally. The vulnerability was published on [cvePublishedAt]2026-06-09T17:17:29.097Z[/cvePublishedAt] and last modified on [cveModifiedAt]2026-06-11T18:40:43.393Z[/cveModifiedAt].

Vendor
Microsoft
Product
Windows 11 version 23H2
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-06-11
Advisory published
2026-06-09
Advisory updated
2026-06-11

Who should care

This vulnerability affects multiple versions of Windows 11 and Windows Server 2025. Users of these systems should apply patches or mitigations as available.

Technical summary

The vulnerability is an out-of-bounds read issue in the Windows Application Identity (AppID) Subsystem. This could allow an authorized attacker to disclose information locally. The Common Vulnerabilities and Exposures (CVE) score is 5.5, indicating a MEDIUM severity level. The CVSS vector is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Defensive priority

Apply patches or mitigations as available. This vulnerability requires local access and authorization to exploit.

Recommended defensive actions

  • Apply patches or mitigations as available from Microsoft.
  • Ensure that only authorized users have access to affected systems.

Evidence notes

Evidence for this CVE comes from the National Vulnerability Database (NVD) and Microsoft's security advisories.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-45604 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-45604

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

  • CVE-2026-45604 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-45604

    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.