Skip to main content
Live Webinar with SANS (June 25)— Agentic CTI Automation for Fun & ProfitRegister Free
Mallory
High

Windows Kernel Elevation of Privilege Vulnerability

IdentifiersCVE-2026-33841CWE-122· Heap-based Buffer Overflow

CVE-2026-33841 is a Windows Kernel elevation of privilege vulnerability caused by a heap-based buffer overflow. Microsoft describes the flaw as a heap-based buffer overflow in the Windows Kernel that can be exploited by an authorized local attacker. Successful exploitation can cross a privilege boundary from a contained or sandboxed low-integrity execution context, including AppContainer-related scenarios, and elevate the attacker’s privileges on the affected system. Microsoft rated the issue Important and assigned CVSS v3.1 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Share:
For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows a local attacker with low privileges to elevate privileges on the affected Windows system, potentially escaping a low-integrity sandboxed context and obtaining Medium Integrity Level or High Integrity Level access. Reporting also indicates the flaw may be abused to reach SYSTEM in practical attack chains. The CVSS impact metrics indicate high confidentiality, integrity, and availability impact once exploited.

Mitigation

If you can’t patch tonight, do this now.

No specific vendor mitigation beyond patching was provided in the supplied content. Until the update is applied, reduce exposure by limiting local code execution opportunities for untrusted users, minimizing the ability to run code inside low-integrity or sandboxed contexts that could be used as a launch point, enforcing least privilege, and monitoring for anomalous privilege-escalation behavior on affected Windows hosts.

Remediation

Patch, then assume compromise.

Apply the official Microsoft security update for CVE-2026-33841. Microsoft states that an official fix was available at advisory publication through the Microsoft Security Response Center Security Update Guide. Standard remediation should include prioritizing patch deployment on systems where untrusted local code execution is possible, including multi-user workstations, terminal environments, developer systems, and hosts running sandboxed applications.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Microsoft CorporationWindows 10 21h2operating_system
Microsoft CorporationWindows 10 22h2operating_system
Microsoft CorporationWindows 11 23h2operating_system
Microsoft CorporationWindows 11 24h2operating_system
Microsoft CorporationWindows 11 25h2operating_system
Microsoft CorporationWindows 11 26h1operating_system
Microsoft CorporationWindows Kerneloperating_system
Microsoft CorporationWindows Server 2022operating_system
Microsoft CorporationWindows Server 2022 23h2operating_system
Microsoft CorporationWindows Server 2025operating_system
Microsoft CorporationWindows Server 23h2operating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.