CVE-2023-21674: Microsoft Windows 10 Version 1809 · Use After Free
Affects Microsoft Windows 10 Version 1809Source CVE Database V5
Exploited in the wild · KEV due 31 Jan 2023 · public exploit available · 34% EPSS : apply the vendor's fix or mitigations to Microsoft Windows 10 Version 1809 now.
Data as of 26 Oct 2026, 14:05 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
- EPSS
- 34.2% chance of exploitation in 30 days – higher than 98% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:CExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 10 Jan 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: evidence found.
Listed in CISA KEV the same day as disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Microsoft Corporation
, 28 days before disclosure
CVE published
on cve.org
, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, the same day as disclosure
KEV remediation due
US federal deadline
, 21 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Apply updates per vendor instructions.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Windows 10 Version 1809 | Affected
| Fixed in– |
Description
Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability