CVE-2026-40378 in Windows

Summary

by MITRE • 07/14/2026

Memory allocation with excessive size value in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network.

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• Responsible: Microsoft
• Reservation: 04/12/2026
• Disclosure: 07/14/2026
• Moderation: accepted
• Entry: VDB-378463
• CPE: ready
• CWE: CWE-770 (confirmed)
• CVSS: 7.5 (VulDB)
• EPSS: 0.00000
• KEV: no
• Activities: low
• Sector: Police, Agriculture, ...

Sources

• MITRE: https://www.cve.org/CVERecord?id=CVE-2026-40378
• NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40378
• CVE Details: https://www.cvedetails.com/cve/CVE-2026-40378/