Medium

Windows Kernel Information Disclosure Vulnerability

IdentifiersCVE-2026-21222CWE-532· Insertion of Sensitive Information…

CVE-2026-21222 is an information disclosure vulnerability in the Windows Kernel. The provided content states that the flaw is caused by insertion of sensitive information into a log file, allowing sensitive data to be written to logs where it can later be accessed. Microsoft and third-party references in the content describe it as a local information disclosure issue affecting Windows Kernel components on supported Windows versions.

For your environment

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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 an authorized local attacker to disclose sensitive information from log files. The primary impact is exposure of data that should not be logged, which could aid further local post-exploitation activity, reconnaissance, or access to sensitive system or application state.

Mitigation

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

No specific mitigation or workaround for CVE-2026-21222 is provided in the supplied content. In the absence of a vendor workaround, limit local access to authorized users only, restrict access to relevant log files, and monitor for unexpected exposure of sensitive data in logs until patches are deployed.

Remediation

Patch, then assume compromise.

Apply the Microsoft February 2026 security updates for affected Windows versions. The provided content indicates Microsoft released patches for supported product versions and recommends prompt installation, with verification through Windows Update, Update History, or standalone packages from the Microsoft Update Catalog if necessary.

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 1607operating_system

Microsoft CorporationWindows 10 1809operating_system

Microsoft CorporationWindows 10 21h2operating_system

Microsoft CorporationWindows 10 22h2operating_system

Microsoft CorporationWindows 11 23h2operating_system

Microsoft CorporationWindows 11 24h2operating_system

Microsoft CorporationWindows Server 2012operating_system

Microsoft CorporationWindows Server 2012 R2operating_system

Microsoft CorporationWindows Server 2016operating_system

Microsoft CorporationWindows Server 2019operating_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.

ACTIVITY FEED

Recent activity

6 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

6 SOURCESView more in app

nsfocus globalNews

Mar 4, 2026

Microsoft’s February Security Update of High-Risk Vulnerability Notice for Multiple Products - NSFOCUS, Inc., a global network and cyber security leader, protects enterprises and carriers from advanced cyber attacks.

An information disclosure vulnerability affecting the Windows Kernel.

thecyberexpress com vulnerabilitiesNews

Feb 11, 2026

Microsoft Patch Tuesday February 2026 Fixes 6 Zero-Days

An information disclosure vulnerability in the Windows kernel.

bleeping computerNews

Feb 10, 2026

Microsoft February 2026 Patch Tuesday fixes 6 zero-days, 58 flaws

An information disclosure vulnerability in Windows Kernel (no additional details provided in the content).

zerodayinitiative blogNews

Feb 10, 2026

Zero Day Initiative - The February 2026 Security Update Review

An information disclosure vulnerability in the Windows Kernel.

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.

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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 activity1

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

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2026-21222

NVD

nvd.nist.gov/vuln/detail/CVE-2026-21222

MITRE CWE · CWE-532

Insertion of Sensitive Information into Log File

Vendor Advisory

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21222