CVE-2026-45584

Published May 20, 2026

Last updated 2 months ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-45584 is identified as a heap-based buffer overflow vulnerability found within Microsoft Defender, specifically impacting the Microsoft Malware Protection Engine. This flaw allows an unauthorized attacker to execute code over a network. The vulnerability stems from improper input validation and memory management, particularly when processing malicious inputs that exceed allocated buffer boundaries in heap memory structures. Exploitation of this weakness can lead to attackers overwriting adjacent memory locations and potentially injecting malicious code that executes with the privileges of the Defender process.

Description: Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.
Source: secure@microsoft.com
NVD status: Analyzed
Products: malware_protection_engine

Risk scores

CVSS 3.1

Type: Primary
Base score: 8.1
Impact score: 5.9
Exploitability score: 2.2
Vector string: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: HIGH

Weaknesses

secure@microsoft.com: CWE-122

Hype score: Not currently trending

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:microsoft:malware_protection_engine:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "AD1882FA-1447-46F7-A592-142F55820A60",
            "versionEndExcluding": "1.1.26040.8",
            "versionStartIncluding": "1.1.26030.3008",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.