CVE-2026-70027
Microsoft Windows 10 21h2: heap buffer overflow
- Risk score
- 62/100
- CVSS
- 7.8 v3.1
- Exploit chance (30 days)
- 0.3%
- Published
- 13 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- Heap-based buffer overflow in Windows Subsystem for Linux allows an authorized attacker to elevate privileges locally.
- Affected
- Microsoft Windows 10 21h2
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Story map
At a glance
Microsoft Windows 10 21h2: Amber, patch this week. Missing authorization in Windows AppX Deployment Extensions allows an authorized attacker to elevate privileges locally.
The flaws
- CVE-2026-70027: Heap buffer overflow (CVSS 7.8 · EPSS 0%)
- CVE-2026-69945: Missing authorisation (CVSS 8.8 · EPSS 0%)
- CVE-2026-97798: Improper neutralization of argument delimiters in a command ('argument injection') in Windows Error… (CVSS 7.8 · EPSS 0%)
- CVE-2026-96309: Use-after-free (CVSS 7.8 · EPSS 0%)
The fix
Fix: Apply the vendor's security update; see the linked advisory.
Who is exposed: Microsoft Windows 10 21h2
Where it stands
- No known exploitation
Connects to
- Same weakness: Heap buffer overflow (CWE-122). 399 other warnings in 30 days
- Same product: Earlier Microsoft Windows 10 21h2 warnings. 19 in the last 90 days
Why it is Amber
- CVSS 7.8 high
- On your watchlist: windows server
References
Original description
Heap-based buffer overflow in Windows Subsystem for Linux allows an authorized attacker to elevate privileges locally.
Last activity 13 Oct 2026. Patch Forecast updates every hour.