CVE-2026-21248CWE-122

Windows Hyper-V Remote Code Execution Vulnerability

High · published February 10, 2026

CVSS v3.1
7.3
EPSS
1%
Percentile
70.8
In the wild
Unconfirmed
What it is

⚡ A heap-based buffer overflow lurking in Windows Hyper-V could let an authorized attacker execute code locally — a sneaky little glitch waiting for someone to exploit it! Think of it like a crowded elevator where someone gets a little *too* comfortable and pushes all the buttons at once — it could lead to a chaotic ride! In this case, the attacker can manipulate the heap memory space, potentially gaining control over the system. If an attacker successfully exploits this vulnerability, they could run arbitrary code on the affected Hyper-V host. This means they could potentially take over the machine, wreaking havoc on virtualized environments and compromising sensitive data.

Put simply

Think of it like a crowded elevator where someone gets a little *too* comfortable and pushes all the buttons at once — it could lead to a chaotic ride! In this case, the attacker can manipulate the heap memory space, potentially gaining control over the system. This CVE involves a heap-based buffer overflow within Windows Hyper-V that allows an authorized attacker to execute code by manipulating memory allocation, effectively gaining unauthorized control over the system.

What to do

If an attacker successfully exploits this vulnerability, they could run arbitrary code on the affected Hyper-V host. This means they could potentially take over the machine, wreaking havoc on virtualized environments and compromising sensitive data. To safeguard your systems, ensure you apply the latest security patches from Microsoft as soon as possible. Additionally, review your Hyper-V configurations to limit unauthorized access and enhance the overall security posture of your virtual machines. This is manageable! With the right steps, you can secure your environment quickly and effectively. 🛡️

The record
Technical detail
CVSS v3.1
7.3 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CVSS v4.0
Not supplied
EPSS
0.01327 · 70.8th percentile
Weakness
CWE-122 · Heap-based Buffer Overflow
Published
2026-02-10T17:51Z
EPSS history
Timeline
  • 10 FEB 17:51Z
    Windows Hyper-V Remote Code Execution Vulnerability
    cvelistv5