CVE-2026-45638
High
Published: 09 June 2026
Published
09 June 2026
Modified
11 June 2026
KEV Added
—
Patch
—
CVSS Score v3.1
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score
0.0023
13.6th percentile
Risk Priority
16
60% EPSS · 20% KEV · 20% CVSS
Summary
CVE-2026-45638 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 7.8 (High).
Operationally, ranked at the 13.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-35564
Vulnerability details
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
microsoft
windows 10 1607
≤ 10.0.14393.9234 · ≤ 10.0.14393.9234
microsoft
windows 10 1809
≤ 10.0.17763.8880 · ≤ 10.0.17763.8880
microsoft
windows 10 21h2
≤ 10.0.19044.7417 · ≤ 10.0.19044.7417 · ≤ 10.0.19044.7417
microsoft
windows 10 22h2
≤ 10.0.19045.7417 · ≤ 10.0.19045.7417 · ≤ 10.0.19045.7417
microsoft
windows 11 23h2
≤ 10.0.22631.7219 · ≤ 10.0.22631.7219
microsoft
windows 11 24h2
≤ 10.0.26100.8655 · ≤ 10.0.26100.8655
microsoft
windows 11 25h2
≤ 10.0.26200.8655 · ≤ 10.0.26200.8655
microsoft
windows 11 26h1
≤ 10.0.28000.2269 · ≤ 10.0.28000.2269
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
≤ 10.0.14393.9234
+3 more product configuration(s) — see NVD for full list
Mitigating Controls
No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.