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.
CVE-2026-56649
MEDIUMPre-NVD 5.95.9—Trending — 5 sources updated this week
EchelonGraph scoreHIGH confidence
Score 5.9 from GitHub Security Advisory published 2026-07-14. a secondary CVSS source baseline 5.9; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
5.9
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 5.9Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.9
- EG Score
- 5.9(high)
- EPSS
- 46.6%
- KEV
- Not listed
Published
July 14, 2026
Last Modified
July 15, 2026
Advisory Details (1)
Auto-updated Jul 15, 2026Patch available. Sources: microsoft.
microsoft Patch Available
Security Update Guide - Microsoft Security Response Center
Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56649Vendor Advisories for CVE-2026-56649(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(1)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Data Freshness Timeline
(refreshed 8× in last 7d / 8× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:25 UTCEG score recompute
- 2026-07-15 16:25 UTCVendor advisory
- 2026-07-15 16:24 UTCGHSA enrichment
- 2026-07-14 17:42 UTCEG score recompute
- 2026-07-14 17:42 UTCVendor advisory
- 2026-07-14 17:40 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-56649?
CVE-2026-56649 is a medium vulnerability published on July 14, 2026. 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.
When was CVE-2026-56649 disclosed?
CVE-2026-56649 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56649 actively exploited?
CVE-2026-56649 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 46.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56649?
CVE-2026-56649 has a CVSS v4.0 base score of 5.9 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-56649?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56649, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-56649
Is Your Infrastructure Affected by CVE-2026-56649?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.