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Mallory
MediumCISA KEVExploited in the wildPublic exploit

Microsoft Windows Desktop Window Manager Information Disclosure Vulnerability

IdentifiersCVE-2026-20805CWE-200· Exposure of Sensitive Information…

CVE-2026-20805 is an information disclosure vulnerability in Microsoft Windows Desktop Window Manager (DWM). According to the provided content, the flaw allows a local, authorized/authenticated attacker to disclose sensitive information by leaking a section address from a remote ALPC port residing in user-mode memory. Public reporting in the supplied material consistently describes the issue as exposing user-mode memory address information rather than directly enabling code execution. The vulnerability affects multiple supported Windows client and server releases, including Windows 10, Windows 11, and Windows Server versions listed in the January 2026 updates.

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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 discloses sensitive memory address information from user-mode memory, specifically a section address associated with a remote ALPC port. This can weaken exploit mitigations such as ASLR and improve the reliability of follow-on exploitation, making the flaw useful as part of a broader exploit chain. The provided content also notes active exploitation in the wild and CISA KEV inclusion, indicating real-world attacker interest despite the vulnerability's moderate CVSS score.

Mitigation

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

If immediate patching is not possible, prioritize exposure reduction by limiting local attacker access, enforcing least privilege, restricting interactive logon where unnecessary, and monitoring for suspicious local activity that may indicate exploit chaining. Because the issue is already patched and actively exploited, patching is the primary mitigation. If compromise is suspected, perform incident response and scoping, as installing updates does not remediate prior exploitation.

Remediation

Patch, then assume compromise.

Apply Microsoft's January 2026 security updates for affected Windows versions. The provided content references the relevant update articles/KBs for affected platforms, including KB5074109, KB5073450, KB5073457, KB5073723, KB5073722, KB5073696, KB5073698, KB5073455, and KB5073724, depending on OS version. Organizations should verify deployment across all affected Windows client and server systems and prioritize remediation because the vulnerability was reported as actively exploited and added to the CISA KEV catalog.
PUBLIC EXPLOITS

Exploits

No valid public exploits. Mallory filtered out 5 candidates as fakes, detection scripts, or README-only repos.

VALID 0 / 5 TOTALView more in app

All candidate exploits were filtered out by Mallory's validation.

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 11 25h2operating_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.

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 signatures3

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 activity72

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