# CVE-2026-105726: Microsoft Defender out-of-bounds read information disclosure

Source: https://junglewise.ai/threats/cve-2026-105726-out-of-bounds-read-in-microsoft-defender-allows-an-authorized  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-105726 · Severity: medium · CVSS 5.5 · Published 2026-10-13

Microsoft Defender, which protects Windows systems from malware and threats, contains an out-of-bounds read vulnerability that allows an authenticated attacker to read sensitive information on a local machine. An attacker with local access could exploit this flaw to extract confidential data that would normally be protected, such as system credentials or private files.

Technologies: [Microsoft Defender](https://junglewise.ai/threats/technologies/defender). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-105726 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105726 being exploited in the wild.

**How severe is CVE-2026-105726?** Medium severity, with a CVSS score of 5.5, published 13 October 2026.

**Which products and versions are affected?** Microsoft Defender.

**Is there a fix for CVE-2026-105726?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-105726 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-105726?** Check whether you run Microsoft Defender. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds read in Microsoft Defender permits authenticated local attackers to disclose sensitive information. The vulnerability requires local access and attacker authentication, and results in information disclosure without code execution. A patch is available from Microsoft.

## Affected products

- Microsoft Defender

## Timeline

- 2026-10-13: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-105726](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-105726)

## Related threats

- [Microsoft Defender null pointer dereference remote code execution](https://junglewise.ai/threats/cve-2026-122194-null-pointer-dereference-in-microsoft-defender-allows-an)
- [Microsoft Defender Malware Protection Engine elevation of privilege](https://junglewise.ai/threats/cve-2026-69414-microsoft-defender-malware-protection-engine-elevation-of)
- [Microsoft Defender heap buffer overflow](https://junglewise.ai/threats/cve-2026-45584-microsoft-defender-heap-buffer-overflow)
- [Microsoft Defender denial of service](https://junglewise.ai/threats/cve-2026-45498-microsoft-defender-denial-of-service)
- [Microsoft Defender privilege escalation via improper link resolution](https://junglewise.ai/threats/cve-2026-41091-microsoft-defender-privilege-escalation-via-improper-link)