CVE-2026-45599Network attack vector

Unauthenticated code execution via UPnP use-after-free

Published Jun 9, 2026 · Updated Jun 9, 2026

Use-after-free in Universal Plug and Play (upnp.dll) in Microsoft Windows allows remote attackers to execute code over a network. The library accesses an object after releasing its memory, but Microsoft has not published the affected object or lifetime sequence. Exploitation requires no authentication or user interaction and high attack complexity; success executes code in the affected service context.

CVSS severity8.1
High
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Universal Plug and Play (upnp.dll) in Microsoft Windows allows remote attackers to execute code over a network. The library accesses an object after releasing its memory, but Microsoft has not published the affected object or lifetime sequence. Exploitation requires no authentication or user interaction and high attack complexity; success executes code in the affected service context.

The record

CVE
CVE-2026-45599
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-416, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.17763.0 <10.0.17763.8880

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.8880
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.32995
Microsoft · Windows 11, version 25H2version=10.0.26200.0 <10.0.26200.8655
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.9234
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.8655
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.26132
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.26132
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.7417
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.9234
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.7417
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.23228
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.8880
Microsoft · Windows 11, version 26H1version=10.0.28000.0 <10.0.28000.2269
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.7219
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.9234
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.5256
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.32995
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.8880
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.23228

Published CVSS scores

8.1Microsoft CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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