CVE-2026-45584: microsoft malware_protection_engine Heap-based Buffer Overflow

Vulnerability summary

CVE-2026-45584 is a high (CVSS 8.1) Heap-based Buffer Overflow vulnerability in microsoft malware_protection_engine. EPSS estimates a 0.71% chance of exploitation in the next 30 days, higher than 52.5% of scored vulnerabilities.

Timeline

1. 20-05-2026
   PublishedVulnerability first disclosed.
2. 10-08-2026
   Last modifiedVulnerability information updated.

Description

Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().