CVE-2026-41091

Published May 20, 2026

Last updated 6 hours ago

Overview

Description
Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to elevate privileges locally.
Source
secure@microsoft.com
NVD status
Analyzed
Products
malware_protection_engine

Risk scores

CVSS 3.1

Type
Secondary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Known exploits

Data from CISA

Vulnerability name
Microsoft Defender Link Following Vulnerability
Exploit added on
May 20, 2026
Exploit action due
Jun 3, 2026
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.

Weaknesses

secure@microsoft.com
CWE-59

Social media

Hype score
Not currently trending
  1. Security Bulletin: Multiple Microsoft Defender vulnerabilities (CVE-2026-41091, CVE-2026-45498) are actively exploited in the wild. Update Defender immediately. #ThreatIntel #RedLeggCTI https://t.co/Cw6DrjtED3

    @RedLegg

    20 May 2026

    27 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  2. 米国サイバーセキュリティ・社会基盤安全保障庁(CISA)が既知の悪用された脆弱性カタログに7件追加。10年以上前のAcrobatのCVE-2009-3459及びMSのCVE-2008-4250、CVE-2009-1537、CVE-2010-0249、CVE-2010-0806、並びに多分RedSunのCVE-2

    @__kokumoto

    20 May 2026

    592 Impressions

    0 Retweets

    1 Like

    1 Bookmark

    1 Reply

    2 Quotes

  3. CISA added 7 known exploited vulnerabilities to its KEV Catalog on May 20, including CVE-2026-41091 (Microsoft Defender EoP) and CVE-2026-45498 (Microsoft Defender DoS). FCEB agencies must remediate by the due date per BOD 22-01. #Cybersecurity https://t.co/VBhfvQSnF9

    @battista212

    20 May 2026

    26 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    1 Reply

    0 Quotes

  4. The latest Windows Antivirus Platform 4.18.26040.7 and Engine 1.1.26040.8 fix three security issues, two of them already exploited and publicly available... CVE-2026-41091 (RedSun) CVE-2026-45498 (UnDefend) CVE-2026-45584 (???) #MDE #MDAV https://t.co/yDSi6HaTZK

    @fabian_bader

    20 May 2026

    563 Impressions

    1 Retweet

    7 Likes

    2 Bookmarks

    0 Replies

    0 Quotes

  5. 🚨 7 new CISA KEV adds today CVE-2026-45498, CVE-2026-41091, CVE-2010-0806, CVE-2010-0249, CVE-2009-3459, CVE-2009-1537, CVE-2008-4250 https://t.co/0StDFCzdCI #boarnet #cybersecurity #cisakev #cve #threatintelligence #malware

    @boarnetio

    20 May 2026

    0 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

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