HOMEVULNERABILITIESCVE-2026-45498
HIGHCISA KEVIN THE WILD

CVE-2026-45498

Published: May 20, 2026· Updated: May 26, 2026

7.5
CVSS v3.1
EPSS:3.21%probability of exploitation in 30 daysPercentile:87.2th

Official Description

Microsoft Defender Denial of Service Vulnerability

NVD Source

Technical Analysis

CVE-2026-45498 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CISA has added CVE-2026-45498 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Microsoft1 product
defender antimalware platform
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

ACTIVE EXPLOITATIONConfirmed exploitation in the wild
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45498
ADVISORYhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45498

News & Research Mentioning CVE-2026-45498

CISA Adds Seven Known Exploited Vulnerabilities to Catalog
CISA Alerts· May 20, 2026

CISA has added seven new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2008-4250 Microsoft Windows Buffer Overflow Vulnerability CVE-2009-1537 Microsoft DirectX NULL Byte Overwrite Vulnerability CVE-2009-3459 Adobe Acrobat and Reader Heap-Based Buffer Overflow Vulnerability CVE-2010-0249 Microsoft Internet Explorer Use-After-Free Vulnerability CVE-2010-0806 Microsoft Internet Explorer Use-After-Free Vulnerability CVE-2026-41091 Microsoft Defender Elevation of Privilege Vulnerability CVE-2026-45498 Microsoft Defender Denial of Service Vulnerability These types of vulnerabilities are frequent attack vectors for malicious cyber actors and pose significant risks to the federal enterpri [xlite_meta score:63 src:CISA Alerts xlite_fp:75dcd75a228f8d5c7ae44bdeae2e67fd9beb1fc70823543e8283fbf2ed7bb584]

All References (2)

→
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45498Vendor Advisory
→
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45498Third Party Advisory · US Government Resource

Quick Facts

CVE IDCVE-2026-45498
CVSS Score7.5 / 10
SeverityHIGH
CISA KEVYES — Active Exploitation
ExploitIN THE WILD
EPSS (30d)3.21%
Affected1 vendor
PublishedMay 20, 2026

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-45498 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
  • !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
  • !Active exploitation confirmed — treat as P1
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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