CVE-2026-50300: Windows DWM Core Library Information Disclosure Vulnerability

mediumCVSS 5.5CVE-2026-50300

Integer underflow (wrap or wraparound) in Windows Kernel allows an authorized attacker to disclose information locally.

CSIRTS triage

vendor: Microsoft product: Windows Kernel Information disclosure

What: Integer underflow (wrap or wraparound) in Windows Kernel allows an authorized attacker to disclose information locally.
Who is affected: Authorized users of the Windows Kernel.
Urgency: Remediation is medium urgency due to the potential for information disclosure, but it is not currently exploited.
Action: Install the latest security updates from Microsoft.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 5.5
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50300

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-503000.30% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 22% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-50300	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownexploitedNCSC-2026-0231 [1.00] [M/H] Vulnerabilities fixed in Microsoft Windowsncsc-nl
mediumCVE-2026-50300: Integer underflow (wrap or wraparound) in Windows Kernel allows an authorized attacker to disc…nvd

Recent advisories for Windows DWM Core

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

mediumCVE-2026-50437: Out-of-bounds read in Windows DWM Core Library allows an authorized attacker to disclose infor…nvd · 2026-07-14
mediumCVE-2026-50437: Windows DWM Core Library Information Disclosure Vulnerabilitymsrc · 2026-07-14
highCVE-2026-44808: Windows DWM Core Library Elevation of Privilege Vulnerabilitymsrc · 2026-06-09
mediumCVE-2026-44814: Windows DWM Core Library Information Disclosure Vulnerabilitymsrc · 2026-06-09
highCVE-2026-42983: Windows DWM Core Library Elevation of Privilege Vulnerabilitymsrc · 2026-06-09
highCVE-2026-42905: Windows DWM Core Library Elevation of Privilege Vulnerabilitymsrc · 2026-06-09