🛡️ CVE-2026-40377 — windows-10-1607

🟠 CVSS 7.8 — High ✅ No Known Exploit NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Heap-based buffer overflow in Windows Cryptographic Services allows an authorized attacker to elevate privileges locally.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Affected software

CVE-2026-40377 is recorded against 15 packages.

  • unknown
  • windows-10-1607 (fixed in 10.0.14393.9140)
  • windows-10-1809 (fixed in 10.0.17763.8755)
  • windows-10-21h2 (fixed in 10.0.19044.7291)
  • windows-10-22h2 (fixed in 10.0.19045.7291)
  • windows-11-23h2 (fixed in 10.0.22631.7079)
  • windows-11-24h2 (fixed in 10.0.26100.8390)
  • windows-11-25h2 (fixed in 10.0.26200.8390)
  • windows-11-26h1 (fixed in 10.0.28000.2113)
  • windows-server-2012
  • windows-server-2016 (fixed in 10.0.14393.9140)
  • windows-server-2019 (fixed in 10.0.17763.8755)
  • windows-server-2022 (fixed in 10.0.20348.5074)
  • windows-server-2022-23h2 (fixed in 10.0.25398.2330)
  • windows-server-2025 (fixed in 10.0.26100.32772)

Timeline and source

Published on 12 May 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

msrc.microsoft.com

Details

Severity High
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2026-05-12
Updated 2026-08-11
Modified N/A
Fix URL N/A

Affected Packages

Software From version Fixed in
unknown
windows-10-1607 10.0.14393.9140
windows-10-1809 10.0.17763.8755
windows-10-21h2 10.0.19044.7291
windows-10-22h2 10.0.19045.7291
windows-11-23h2 10.0.22631.7079
windows-11-24h2 10.0.26100.8390
windows-11-25h2 10.0.26200.8390
windows-11-26h1 10.0.28000.2113
windows-server-2012
windows-server-2016 10.0.14393.9140
windows-server-2019 10.0.17763.8755
windows-server-2022 10.0.20348.5074
windows-server-2022-23h2 10.0.25398.2330
windows-server-2025 10.0.26100.32772

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