CVE tracker / CVE-2026-69588
CVE-2026-69588
CVE-2026-69588 is the Windows TCP/IP Denial of Service Vulnerability. Microsoft rates it Important, CVSS 7.5. It is not in CISA's Known Exploited Vulnerabilities catalog. Published September 8, 2026.
Risk summary
Microsoft describes it: “Missing release of memory after effective lifetime in Windows TCP/IP allows an unauthorized attacker to deny service over a network.”
How to fix it
Microsoft lists 12 affected products and the update that fixes each:
- KB5122871 · fixed build 10.0.26100.33438
Windows Server 2025, Windows Server 2025 (Server Core installation) - KB5122880 · fixed build 10.0.22631.7582
Windows 11 Version 23H2 for x64-based Systems, Windows 11 Version 23H2 for ARM64-based Systems - KB5122882 · fixed build 10.0.20348.5622
Windows Server 2022 (Server Core installation), Windows Server 2022 - KB5124008 · fixed build 10.0.26100.9445, 10.0.26200.9445
Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 25H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems - KB5124012 · fixed build 10.0.28000.2954
Windows 11 version 26H1 for x64-based Systems, Windows 11 Version 26H1 for ARM64-based Systems
What Microsoft changed
- September 8, 2026: Information published.
Details
- Weakness
- CWE-401: Missing Release of Memory after Effective Lifetime
- Publicly disclosed (Microsoft)
- No
- Exploited (Microsoft)
- No
- Known exploited (CISA KEV)
- Not listed
- Published
- September 8, 2026
- Last revised
- September 8, 2026
Get told when this changes
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References
From Microsoft, CISA, NVD and FIRST data; the Microsoft details were read when this page was opened. Check the references above before you act.