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CVE-2026-45635 Microsoft CVE debrief

CVE-2026-45635 is a HIGH severity vulnerability in Microsoft Windows. A use after free vulnerability in Universal Plug and Play (upnp.dll) allows an attacker to execute code over a network. The vulnerability has a CVSS score of 8.1 and was published on 2026-06-09T17:17:30.100Z. The vulnerability affects multiple versions of Microsoft Windows, including Windows 10, Windows 11, and Windows Server.

Vendor
Microsoft
Product
Windows
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-07-09
Advisory published
2026-06-09
Advisory updated
2026-07-09

Who should care

Administrators and users of Microsoft Windows, particularly those with exposure to Universal Plug and Play (UPnP) functionality, should be aware of this vulnerability.

Technical summary

The vulnerability is a use after free issue in the upnp.dll component of Microsoft Windows. This type of vulnerability occurs when a program uses memory after it has been freed, allowing an attacker to potentially execute arbitrary code.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches from Microsoft as soon as possible, particularly for systems exposed to UPnP functionality.
  • Review and limit exposure to UPnP if not required.
  • Monitor network traffic for suspicious activity related to UPnP.

Evidence notes

The CVE record and NVD detail pages provide comprehensive information about the vulnerability, including affected versions and potential mitigations.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-45635 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-45635

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

  • CVE-2026-45635 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-45635

    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.