Buffer overflow in Microsoft Malware Protection Engine
CVE-2026-45584
Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (52.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.007 · change: -0.001
Affected products
- Microsoft Malware Protection Engine
- Microsoft Malware Protection Engine — versions 1.1.0.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- Microsoft Defender Remote Code Execution Vulnerability (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-45584?
- CVE-2026-45584 is a high-severity vulnerability in Microsoft Malware Protection Engine, classified under Heap-based Buffer Overflow. CVSS score: 8.1/10. Published 2026-05-20.
- How severe is CVE-2026-45584?
- High severity. CVSS v3 base score is 8.1 out of 10.
- Is CVE-2026-45584 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.