CVE-2026-45584: Microsoft Defender Remote Code Execution Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-08 00:03 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.
Description quoted from the CVE record (assigned by microsoft, published 2026-05-20).
Weakness: CWE-122: Heap-based Buffer Overflow
How it can be exploited
Exploitable over the network with high attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: total.
Public exploit evidence (Exploit Observer)
Exploit Observer found 1 code repository naming this CVE.
Code repositories that name a CVE are often scanners, copies or fakes, and some are malware. Read the code before running anything.
See all 6 references on Exploit Observer
Live scores
- EPSS
- 0.009
low predicted chance of attack - VEDAS
- 0.055
little exploit evidence - On CISA KEV
- Not listed
- Detection rule
- No public rule yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Microsoft Malware Protection Engine | from 1.1.0.0 before 1.1.26040.8 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
Fixed versions stated in the CVE record: 1.1.26040.8.
Vendor guidance:
- Microsoft Defender Remote Code Execution Vulnerability (vendor-advisory, patch)
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
Advisories on this CVE
- Microsoft Defender CVE-2026-41091 and CVE-2026-45498: exploited “RedSun” privilege escalation and “UnDefend” (full advisory)
References
Vendor advisories and patches
- Microsoft Defender Remote Code Execution Vulnerability (vendor-advisory, patch)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.
Supporting partners
