Unauthenticated code execution via heap buffer overflow
Published May 20, 2026 · Updated May 20, 2026
Heap-based buffer overflow in Microsoft Malware Protection Engine before 1.1.26040.8 allows remote attackers to execute code over a network. Microsoft has not disclosed the affected routine, triggering input, or operation that exceeds the heap allocation. Exploitation requires no account and unspecified high-complexity conditions; successful attacks execute code on the protected host.
Summary
What happened
Heap-based buffer overflow in Microsoft Malware Protection Engine before 1.1.26040.8 allows remote attackers to execute code over a network. Microsoft has not disclosed the affected routine, triggering input, or operation that exceeds the heap allocation. Exploitation requires no account and unspecified high-complexity conditions; successful attacks execute code on the protected host.
The record
- CVE
- CVE-2026-45584
- Published
- May 20, 2026
- Updated
- May 20, 2026
- Vendor
- Microsoft
- Product
- Microsoft Malware Protection Engine
- Classifications
- CWE-122, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 20, 2026CVE publishedPublication date reported by the CVE source.
- May 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=-
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo