CVE-2026-56650: Windows Network File System Elevation of Privilege Vulnerability

highCVSS 7.8CVE-2026-56650

Heap-based buffer overflow in Windows Network File System allows an authorized attacker to elevate privileges locally.

CSIRTS triage

vendor: Microsoft product: Windows Network File System Privilege escalation

What: Heap-based buffer overflow in Windows Network File System allows an authorized attacker to elevate privileges locally.
Who is affected: Authorized users of Windows Network File System are affected.
Urgency: Remediation is high urgency due to the potential for privilege escalation.
Action: Apply the latest security updates for Windows Network File System.

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: high — CVSS 7.8
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56650

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-2026-566500.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-56650	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

Recent advisories for Windows Network File

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.

highCVE-2026-56650: Heap-based buffer overflow in Windows Network File System allows an authorized attacker to ele…nvd · 2026-07-14
mediumCVE-2026-56649: Concurrent execution using shared resource with improper synchronization ('race condition') in…nvd · 2026-07-14
highCVE-2026-56648: Time-of-check time-of-use (toctou) race condition in Windows Network File System allows an aut…nvd · 2026-07-14
highCVE-2026-56194: Heap-based buffer overflow in Windows Network File System allows an authorized attacker to ele…nvd · 2026-07-14
mediumCVE-2026-56649: Windows Network File System Remote Code Execution Vulnerabilitymsrc · 2026-07-14