CVE-2026-69761 is a high severity flaw in the TCP/IP stack in Windows, scored 7.1 by the record. Per the NVD record, it allows an authorized attacker to elevate privileges over a network. The record does not state a fixed build, so use the Microsoft advisory for the update that applies to your version and apply it.
What's affected
The NVD record lists these affected products: Windows 10 1607; Windows 10 1809; Windows 10 21h2; Windows 10 22h2; Windows 11 23h2; Windows 11 24h2; Windows 11 25h2; Windows 11 26h1.
The record describes the issue this way: Use after free in Windows TCP/IP allows an authorized attacker to elevate privileges over a network.
The record gives a CVSS 3.1 base score of 7.1 (HIGH), published 2026-09-08, with the vector CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H. The vector reads as follows. Access is over the network, attack complexity is high, and privileges required are low. A user has to take some action. Scope is unchanged. Confidentiality, integrity and availability impact are high, high and high.
Microsoft publishes fixed builds on its Security Update Guide, and that page needs a browser to render, so we could not read it automatically. Take version details from there. Where Microsoft's advisory differs from this record on severity or versions, trust the advisory and note the difference in your own tracking.
How to check if you're exposed
Start with the exact Windows build on each machine, then compare it to the fixed build or KB listed in the Microsoft advisory.
winver
Get-ComputerInfo | Select-Object WindowsProductName, OsVersion, OsBuildNumber
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 10
Match the output against the advisory's table for your Windows version. If the fixing KB is not in the hotfix list, treat the machine as exposed until you confirm otherwise. For a fleet, run the same query through your endpoint management tool instead of machine by machine.
What to do now
- Read the Microsoft advisory and note the fixing update for each Windows version you run.
- Approve and deploy that update, starting with servers and shared workstations.
- Reboot where the update requires it and confirm the new build number.
- Re-run the exposure check and record machines that could not be patched yet.
Why it matters
CWE-416 (use after free) describes a weakness where memory is used after it has been released, so the program acts on data it no longer owns.
Operating system flaws matter because the component runs with high privileges on every machine that has it, and a fleet is slow to patch. The record's own scoring tells you how to rank this one: read the attack vector and privileges lines above, then compare with the machines you actually run.
A second TCP/IP use after free, CVE-2026-69757 and CVE-2026-69761, was published the same day with the same score. Check that your update covers both IDs.
The record's kev field is false, so the record does not list this CVE in CISA's Known Exploited Vulnerabilities catalog, and no fetched advisory said it was exploited. That is a snapshot, not a promise, so keep watching.
Safeguard's Gold page for this CVE tracks the record, and the free in-browser scan can check dependency manifests for related issues. Reachability analysis helps with libraries, though it does not apply to operating system patches.
Quick check
Does this CVE appear in the CISA Known Exploited Vulnerabilities list?
The record's kev field is false, so it is not listed in CISA's catalog as of the record we hold. That can change, so check the catalog if you are prioritizing.
Is a fixed version listed in the record?
No. The record names affected Windows products but not fixed builds. Use the Microsoft advisory for the update that applies to each version.
Sources
- Microsoft Security Update Guide entry for CVE-2026-69761 (the page did not return readable advisory text to our automated fetch, so confirm details there)
- NVD record for CVE-2026-69761 as supplied in the Safeguard batch data
Last reviewed: 18 October 2026.
