CVE tracker / CVE-2026-71336
CVE-2026-71336
CVE-2026-71336 is the Windows Work Folder Service Remote Code Execution Vulnerability. Microsoft rates it Important, CVSS 8.8. It is not in CISA's Known Exploited Vulnerabilities catalog. Published September 8, 2026.
Risk summary
Microsoft describes it: “Integer overflow or wraparound in Windows Work Folder Service allows an authorized attacker to execute code over a network.”
How to fix it
Microsoft lists 14 affected products and the update that fixes each:
- KB5122871 · fixed build 10.0.26100.33438
Windows Server 2025, Windows Server 2025 (Server Core installation) - KB5122876 · fixed build 10.0.17763.9245
Windows Server 2019, Windows Server 2019 (Server Core installation), Windows 10 Version 1809 for x64-based Systems, Windows 10 Version 1809 for 32-bit Systems - KB5122882 · fixed build 10.0.20348.5622
Windows Server 2022 (Server Core installation), Windows Server 2022 - KB5123066 · fixed build 6.3.9600.23398
Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation) - KB5123099 · fixed build 10.0.14393.9512
Windows Server 2016 (Server Core installation), Windows Server 2016, Windows 10 Version 1607 for x64-based Systems, Windows 10 Version 1607 for 32-bit Systems
What Microsoft changed
- September 11, 2026: Updated an acknowledgement. This is an informational change only.
- September 8, 2026: Information published.
Details
- Weakness
- CWE-190: Integer Overflow or Wraparound
- Publicly disclosed (Microsoft)
- No
- Exploited (Microsoft)
- No
- Known exploited (CISA KEV)
- Not listed
- Published
- September 8, 2026
- Last revised
- September 11, 2026
Get told when this changes
Senserva Watch emails Microsoft security and patch alerts when something moves: a new exploitation report, a revised fix, a known issue. Free, one email address.
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.