CVE-2026-56649: Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Network File System allows an unauthorized attacker to execute code over a ne

mediumCVSS 5.9CVE-2026-56649

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Network File System allows an unauthorized attacker to execute code over a network.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 5.9
Published: 2026-07-14
Last updated: 2026-07-17
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-56649

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-2026-566490.65% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 48% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-56649	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-2026-56649: Windows Network File System Remote Code Execution Vulnerabilitymsrc

Recent advisories for Concurrent execution using

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.

unknownCVE-2026-16727: Concurrent Execution using Shared Resource with Improper Synchronization (“Race Condition”) in…nvd · 2026-07-30
highCVE-2026-58598: Concurrent execution using shared resource with improper synchronization ('race condition') in…nvd · 2026-07-16
highCVE-2026-58628: Concurrent execution using shared resource with improper synchronization ('race condition') in…nvd · 2026-07-14
mediumCVE-2026-58543: Concurrent execution using shared resource with improper synchronization ('race condition') in…nvd · 2026-07-14
highCVE-2026-58531: Concurrent execution using shared resource with improper synchronization ('race condition') in…nvd · 2026-07-14
highCVE-2026-58527: Concurrent execution using shared resource with improper synchronization ('race condition') in…nvd · 2026-07-14