Vulnerability in Microsoft Malware_protection_engine
CVE-2026-41091
Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to elevate privileges locally.
EPSS: 0.080 (92.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Microsoft Malware_protection_engine
- Microsoft Malware Protection Engine — versions 1.1.0.0
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
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.
Public proof-of-concept exploits
References
- Microsoft Defender Elevation of Privilege Vulnerability (vendor-advisory, patch, Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-41091?
- CVE-2026-41091 is a high-severity vulnerability in Microsoft Malware_protection_engine, classified under Improper Link Resolution Before File Access. CVSS score: 7.8/10. Published 2026-05-20.
- How severe is CVE-2026-41091?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2026-41091 known to be exploited?
- Yes. CVE-2026-41091 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-05-20), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.