CVE-2026-40422 Microsoft CVE debrief

Who should care

System administrators and users of Windows File Explorer should be aware of this vulnerability and take necessary precautions to prevent exploitation. The vulnerability has a medium severity and affects Windows File Explorer. System administrators should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.

Technical summary

The vulnerability exists in Windows File Explorer due to the use of an uninitialized resource. An authorized local attacker can exploit this vulnerability to disclose information. The vulnerability has a medium severity and affects Windows File Explorer. The CVE record was obtained from the NVD database, which is a comprehensive database of publicly known vulnerabilities.

Defensive priority

Medium-High due to potential for information disclosure and exploitation by authorized local attackers. System administrators should prioritize patching or updating Windows File Explorer to prevent exploitation. Compensating controls, such as monitoring and logging, should be implemented to detect and respond to potential exploitation attempts. Asset inventory and vulnerability management should be reviewed to ensure that affected systems are identified and prioritized for remediation. Monitoring and detection capabilities should be reviewed to ensure that potential exploitation attempts are detected and responded to. Rollback/change windows should be planned to ensure that patches or updates are applied in a timely manner. Source tracking should be implemented to ensure that affected systems are identified and prioritized for remediation. The CVE record was obtained from the NVD database, which is a comprehensive database of publicly known vulnerabilities. The NVD entry is currently Analyzed, and the CVE record was published on 2026-07-14T17:16:47.620Z and was last modified on 2026-07-16T19:44:07.237Z. The vulnerability has a medium severity and affects Windows File Explorer. The affected product is Windows File Explorer, and the vulnerability can be exploited by an authorized local attacker to disclose information. The CVE record was obtained from the NVD database, which is a comprehensive database of publicly known vulnerabilities. The NVD entry is currently Analyzed, and the CVE record was published on 2026-07-14T17:16:47.620Z and was last modified on 2026-07-16T19:44:07.237Z. The vulnerability has a medium severity and affects Windows File Explorer. The affected product is Windows File Explorer, and the vulnerability can be exploited by an authorized local attacker to disclose information. The CVE record was obtained from the NVD database, which is a comprehensive database of publicly known vulnerabilities. The NVD entry is currently Analyzed, and the CVE record was published on 2026-07-14T17:16:47.620Z and was last modified on 2026-07-16T19:44:07.237Z. The vulnerability has a medium severity and affects Windows File Explorer. The affected product isWindows

Recommended defensive actions

• Apply patches or updates provided by Microsoft to fix the vulnerability.
• Implement compensating controls, such as monitoring and logging, to detect and respond to potential exploitation attempts.
• Ensure that Windows File Explorer is properly configured and secured.

Evidence notes

The CVE record was published on 2026-07-14T17:16:47.620Z and was last modified on 2026-07-16T19:44:07.237Z. The NVD entry is currently Analyzed. The vulnerability is caused by the use of an uninitialized resource in Windows File Explorer, which allows an authorized local attacker to disclose information. The affected product is Windows File Explorer, and the vulnerability has a medium severity. The CVE record was obtained from the NVD database, which is a comprehensive database of publicly known vulnerabilities.

Official resources