SYSTEM privilege escalation via remediation link following
Published May 20, 2026 · Updated May 20, 2026
Link-following in Microsoft Malware Protection Engine before 1.1.26040.8 allows local users to elevate privileges to SYSTEM. During privileged remediation of a cloud-tagged file, the engine follows an attacker-controlled junction and redirects its write into a protected path. A low-privileged local account and active Defender scanning are required; successful exploitation permits arbitrary code execution as SYSTEM.
Summary
What happened
Link-following in Microsoft Malware Protection Engine before 1.1.26040.8 allows local users to elevate privileges to SYSTEM. During privileged remediation of a cloud-tagged file, the engine follows an attacker-controlled junction and redirects its write into a protected path. A low-privileged local account and active Defender scanning are required; successful exploitation permits arbitrary code execution as SYSTEM.
The record
- CVE
- CVE-2026-41091
- Published
- May 20, 2026
- Updated
- May 20, 2026
- Vendor
- Microsoft
- Product
- Microsoft Malware Protection Engine
- Classifications
- CWE-59, T1068
- Attack vector
- local
- Privileges
- authenticated
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.
Weakness, pattern, technique
Public exploit references
- RedSun proof-of-conceptfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities Catalog inclusionknown exploited catalog
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