highclosedpatched

Microsoft Defender: Microsoft Defender Link Following Vulnerability

› Microsoft Defender

last updated May 20, 2026

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started: May 20, 2026
closed: May 20, 2026
CVEs: 2
sources: 5

## summary

Microsoft Defender contains a link following vulnerability that allows an authorized attacker to elevate privileges locally. CISA added CVE-2026-41091, CVE-2026-45498 to the Known Exploited Vulnerabilities catalog on 2026-05-20 based on evidence of active exploitation.

severity: Actively exploited (CISA KEV)

## cve ids[2]

CVE-2026-41091 CVE-2026-45498

## affected

See vendor advisory / CISA notes (versions not always listed in KEV feed)

## fixed in

See vendor advisory linked in sources

## timeline[1]

May 20, 2026
CISA added CVE-2026-41091, CVE-2026-45498 to the KEV catalog (due 2026-06-03).

## advisories[5]

## notes & caveats

Derived from CISA KEV JSON feed catalogVersion 2026.10.21. Exact affected/fixed version strings are not always in the KEV record — verify against the vendor advisory URL. startedAt uses dateAdded (exploitation may have begun earlier).

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