CVE-2026-83666: Microsoft Windows 10 Version 1607 · Race Condition
Affects Microsoft Windows 10 Version 1607Source CVE Database V5
Not known to be exploited · CVSS 7.0 High : upgrade to 10.0.14393.9612 soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 10.0.14393.9612, 10.0.17763.9376, 6.2.9200.26434 +3
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 13 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MicrosoftWindows 10 Version 1607 | Affected
| Fixed in
|
| MicrosoftWindows 10 Version 1809 | Affected
| Fixed in
|
| MicrosoftWindows Server 2012 | Affected
| Fixed in
|
| MicrosoftWindows Server 2012 (Server Core installation) | Affected
| Fixed in
|
| MicrosoftWindows Server 2012 R2 | Affected
| Fixed in
|
| MicrosoftWindows Server 2012 R2 (Server Core installation) | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
An official fix is available from Microsoft. Users and administrators should apply the security updates provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83666 to remediate this vulnerability.
Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges locally.