Unauthenticated Remote Heap Buffer Overflow in Microsoft Windows 11 (version 23H2) Rates 9.8 CVSS
Last refreshed2026-10-15
Status: UPDATED
| Advisory ID: CVE-2026-69639
Key Details
CVE
CVE-2026-69639
CVSS Score / Version
9.8 (Critical) / CVSS v3.1
Updated
2026-10-14
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Prose
attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Affected products
see table below
Classified as
CWE-122 (Heap-based Buffer Overflow)
Exploitation prediction (EPSS)
0.79% probability of exploitation in the next 30 days (55% percentile) -- FIRST.org's EPSS model.
Affected Products, Subsystems & Sectors
Vendor
Product
Affected Versions
Patch Status
Microsoft
Windows 11 (version 23H2)
Microsoft
Windows 11 (version 24H2)
Microsoft
Windows 11 (version 25H2)
Microsoft
Windows 11 (version 26H1)
Microsoft
Windows Server 2025
Microsoft
Windows 10 (version 1809)
Microsoft
Windows 10 (version 21H2)
Microsoft
Windows 10 (version 22H2)
Microsoft
Windows Server 2019
Microsoft
Windows Server 2022
Microsoft
Windows 11 Version 26H2
Subsystems
OT Supporting Infrastructure
Sectors
All Sectors
What to Know
Heap-based buffer overflow in Windows Libarchive allows an unauthorized attacker to execute code over a network.
What to Do
Monitor Microsoft's web page for any future patch releases.