CVE-2026-41091

highpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.004 · 38 %ileexploit · PoCDEEURUUS

grimoire priorityP0 · Act now

Exploitable?

Yes · in the wild

CISA KEV · 4 exploits · PoC

Likely / severe?

0.44% (38th) EPSS

CVSS 7.8 · high

Is it mine?

7 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

added 2026-05-20remediate by 2026-06-03

required action Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

EPSS · scored 2026-10-22

Microsoft Defender Link Following Vulnerability

Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to elevate privileges locally.

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.

7.8

010

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

v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · ENISA EU

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · secure@microsoft.com USexploitability 1.8 · impact 5.9

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Hsecondary · CVSS-BT (t0sche)

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/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: active · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-59USCWE-59USCWE-59US

exploits (4)

Public proof-of-concept and weaponised exploit code.

affected products (7)

Products and version ranges known to be affected.

Microsoft Malware Protection Engine <1.1.26040.8all versionscert_bundDE
Microsoft Malware Protection Engine< 1.1.26040.8cert_bundDE
Microsoft Microsoft Malware Protection Engine1.1.0.0 → 1.1.26040.8enisa_euvdEU
Microsoft Corp Microsoft Malware Protection Engine1.1.26030.3008 → 1.1.26040.8fstec_bduRU
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-2026-41091Microsoft Defender Elevation of Privilege 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 (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund msrc_csaf nvd NVD CVE.org MITRE

published 2026-05-20modified 2026-07-24

references (5)

External citations — patches, advisories, analysis.

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41091Patchcnnvd
https://nvd.nist.gov/vuln/detail/CVE-2026-41091 cnnvd
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41091 enisa_euvd
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41091Vendor Advisorynvd
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-41091Third Party AdvisoryUS Government Resourcenvd

scry

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