CVE-2026-45584

highpriority · track · 10EPSS 0.007 · 53 %ileexploit · PoCDEEUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · PoC

Likely / severe?

0.71% (53rd) EPSS

CVSS 8.1 · high

Is it mine?

8 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · cert_bund · msrc_csaf

EPSS · scored 2026-10-23

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

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedMicrosoft Malware Protection Enginemsrc_csaf
1.1.26040.8:Security Update:https://docs.microsoft.com/en-us/microsoft-365/security/defender-endpoint/manage-updates-baselines-microsoft-defender-antivirus?view=o365-worldwide
https://docs.microsoft.com/en-us/microsoft-365/security/defender-endpoint/manage-updates-baselines-microsoft-defender-antivirus?view=o365-worldwide

cvss

Technical severity, 0–10. One row per scoring source.

8.1

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · ENISA EU

v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · secure@microsoft.com USexploitability 2.2 · impact 5.9

v3.17.7highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Psecondary · CVSS-BT (t0sche)

v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · Microsoft Security Response Center US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-122USCWE-122US

exploits (1)

Public proof-of-concept and weaponised exploit code.

96613686/CVE-2026-4558496613686/CVE-2026-45584PoC · poc_in_github

affected products (8)

Products and version ranges known to be affected.

Microsoft Defender Antimalware Platform <4.18.26040.7all versionscert_bundDE
Microsoft Malware Protection Engine <1.1.26040.8all versionscert_bundDE
Microsoft Defender≤ Antimalware Platform <4.18.26040.7cert_bundDE
Microsoft Malware Protection Engine< 1.1.26040.8cert_bundDE
Microsoft Microsoft Malware Protection Engine1.1.0.0 → 1.1.26040.8enisa_euvdEU
Microsoft Microsoft Malware Protection Engineall versionsfixedmsrc_csafUS
Microsoft Microsoft Malware Protection Engine< 1.1.26040.8msrc_csafUS
microsoft malware protection engine1.1.26030.3008 → 1.1.26040.8nvdUScpe:2.3:a:microsoft:malware_protection_engine:*:*:*:*:*:*:*:*

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-1603Microsoft Defender und Malware Protection Engine: Mehrere SchwachstellenDeutsch2026-05-19csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Microsoft Defender und Microsoft Malware Protection Engine ausnutzen, um seine Privilegien zu erhöhen, um beliebigen Code auszuführen und um einen Denial of Service Zustand herbeizuführen.
msrc_CVE-2026-45584Microsoft Defender Remote Code Execution Vulnerability2026-05-19csaf · msrc_csafUS
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund msrc_csaf nvd NVD CVE.org MITRE

published 2026-05-20modified 2026-07-23

references (3)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

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