CVE-2026-54997: Windows SMB Information Disclosure Vulnerability

mediumCVSS 5.5CVE-2026-54997

Use of uninitialized resource in Windows SMB allows an authorized attacker to disclose information locally.

CSIRTS triage

vendor: Microsoft product: Windows SMB Information disclosure

What: Use of uninitialized resource in Windows SMB allows an authorized attacker to disclose information locally.
Who is affected: Authorized users of Windows SMB are affected.
Urgency: Remediation is important due to the medium severity and risk of information disclosure.
Action: Update Windows SMB to the latest version.

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-2026-54997

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-2026-549970.30% 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-2026-54997	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-2026-54997: Use of uninitialized resource in Windows SMB allows an authorized attacker to disclose informa…nvd

Recent advisories for Windows SMB Information

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-2026-50690: Use of uninitialized resource in Windows SMB allows an authorized attacker to disclose informa…nvd · 2026-07-14
mediumCVE-2026-54997: Use of uninitialized resource in Windows SMB allows an authorized attacker to disclose informa…nvd · 2026-07-14
mediumCVE-2026-49801: Use of uninitialized resource in Windows SMB allows an authorized attacker to disclose informa…nvd · 2026-07-14
mediumCVE-2026-50690: Windows SMB Information Disclosure Vulnerabilitymsrc · 2026-07-14
mediumCVE-2026-49801: Windows SMB Information Disclosure Vulnerabilitymsrc · 2026-07-14
criticalexploitedCVE-2019-0703: Microsoft Windows SMB Information Disclosure Vulnerabilitycisa-kev · 2022-05-23