CVE-2026-21248Disclosure(microsoft / windows_10_1607)

MEDIUMCVSS 7.3 · HIGH

Exploit discussion active in current signal (1 latest mentions)

Immediate actions

Prioritize remediation for microsoft windows_10_1607 systems immediately
Hunt for exploitation attempts and persistence artifacts
Increase monitoring for publicly documented tradecraft
Track advisory updates for patch or workaround availability

Recommended action window: High priority (within 72h)

NVD description

Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.

microsoft CVEs Back to dashboard

4.0/ 10 priority

Sources & remediation

Vendor / third-party advisories

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21248

Weakness type (CWE)

CWE-122CWE-787

Priority

MEDIUM

Exploitation

NONE

PoC

YES

Patch

NONE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

windows_10_1607
windows_10_1809
windows_10_21h2
windows_10_22h2

Threat summary

Public PoC and exploit tooling are both present
5 mentions across 3 observed days
Momentum state: stable

What's happening

Exploit tool or code specified in 2 signals
PoC mentioned or linked in 2 signals
Technical details provided in 4 signals
Disclosure: 3 classified signals
Peaked 2d ago at 2 mentions (2026-02-10); latest day: 1
5 total mentions across 3 days

Affected systems

Vendors

microsoft

Products

windows_10_1607windows_10_1809windows_10_21h2windows_10_22h2windows_11_23h2windows_11_24h2windows_11_25h2windows_server_2016windows_server_2019windows_server_2022

Deep dive

Activity timeline5 mentions / 3d

Signal classification2 categories

Disclosure

360.0%

Exploit

240.0%

Referenced assets5 URLs

By indicator

Classification over time

Date	Total	Labels

2026-02-10	2	Disclosure2
2026-02-15	2	Disclosure1Exploit1
2026-06-07	1	Exploit1

Full discourse5 posts

NSA Agent #777@biopunk0124d
Exploit
@encrypted_past CVE-2026-21248 - Windows Hyper-V Ghost Patch Exploit Framework Author: nu11secur1ty Date: 2026-02-13 Target: Windows 11 25H2 Build 26200.7830 (x64) WSL may be another PoC
Post summary
The post announces a Windows Hyper‑V vulnerability (CVE‑2026‑21248) that has an associated exploit framework, with a possible PoC via WSL, but provides no evidence of active exploitation or patch availability.
010101.8K
169 followersView on X
AgniOps@AgniOpsIn236d
Disclosure
🔥 Windows Hyper-V | CVE-2026-21248 A heap overflow in Hyper-V can allow privilege escalation on the host, impacting all guest VMs. Deep technical analysis 👇 https://www.agniops.in/post/windows-11-25h2-hyper-v-cve-2026-21248-heap-overflow-ghost-patch-exploit-framework #WindowsSecurity #HyperV #CVE #Virtualization #ThreatResearch
Post summary
The post announces CVE‑2026‑21248, a heap overflow in Windows Hyper‑V that permits host privilege escalation, and links to a detailed technical analysis.
01010103
1 followersView on X
VulDB 🛡@vuldb240d
Disclosure
The severity is increased for this new vulnerability affecting Microsoft Windows (CVE-2026-21248) https://vuldb.com/?id.345274
Post summary
The text announces a new Windows vulnerability, CVE-2026-21248, and notes its severity has increased, but offers no further technical or patch details.
0001071
2.1K followersView on X
nu11secur1ty@nu11secur1ty1236d
Exploit
Windows 11 25H2 Hyper-V CVE-2026-21248 Heap Overflow + Ghost Patch Exploit Framework - http://CXSecurity.com https://cxsecurity.com/issue/WLB-2026020011
Post summary
The post announces a Windows 11 25H2 Hyper‑V CVE-2026-21248 Heap Overflow exploit framework, linking to a CXSecurity page that likely contains PoC code.
0000087
105 followersView on X
CVE@CVEnew240d
Disclosure
CVE-2026-21248 Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally. https://www.cve.org/CVERecord?id=CVE-2026-21248
Post summary
A heap-based buffer overflow in Windows Hyper‑V that allows local code execution has been disclosed.
00000172
56.5K followersView on X

CPE platform detail15 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

15 of 15 entries

Part	Vendor	Product	Version	Target SW	Target HW
OS	microsoft	windows_10_1607	-	-	x64
OS	microsoft	windows_10_1809	-	-	x64
OS	microsoft	windows_10_21h2	-	-	x64
OS	microsoft	windows_10_22h2	-	-	x64
OS	microsoft	windows_11_23h2	-	-	arm64
OS	microsoft	windows_11_23h2	-	-	x64
OS	microsoft	windows_11_24h2	-	-	arm64
OS	microsoft	windows_11_24h2	-	-	x64
OS	microsoft	windows_11_25h2	-	-	arm64
OS	microsoft	windows_11_25h2	-	-	x64
OS	microsoft	windows_server_2016	-	-	-
OS	microsoft	windows_server_2019	-	-	-
OS	microsoft	windows_server_2022	-	-	-
OS	microsoft	windows_server_2022_23h2	-	-	-
OS	microsoft	windows_server_2025	-	-	-

Explore more

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What researchers are saying

CVE-2026-21248

NSA Agent #777@biopunk0Exploit

The post announces a Windows Hyper‑V vulnerability (CVE‑2026‑21248) that has an associated exploit framework, with a possible PoC via WSL, but provides no evidence of active exploitation or patch availability.

AgniOps@AgniOpsInDisclosure

The post announces CVE‑2026‑21248, a heap overflow in Windows Hyper‑V that permits host privilege escalation, and links to a detailed technical analysis.

VulDB 🛡@vuldbDisclosure

The text announces a new Windows vulnerability, CVE-2026-21248, and notes its severity has increased, but offers no further technical or patch details.

nu11secur1ty@nu11secur1ty1Exploit

The post announces a Windows 11 25H2 Hyper‑V CVE-2026-21248 Heap Overflow exploit framework, linking to a CXSecurity page that likely contains PoC code.

CVE@CVEnewDisclosure

A heap-based buffer overflow in Windows Hyper‑V that allows local code execution has been disclosed.