[KEV] Vulnerability in Microsoft Defender (CVE-2026-45498)
Summary
Vulnerability in Microsoft Defender (CVE-2026-45498). Risk of unauthorized operations or information disclosure. Listed in CISA KEV — actively exploited.
Original description
The description as published by the source.
Microsoft Defender Denial of Service Vulnerability
Source: NIST National Vulnerability Database NVD GitHub Advisory CISA KEV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A weakness called CVE-2026-45498 was discovered in Microsoft Defender.
Severity is Medium (CVSS 4/10). Exploitation requires specific conditions but can cause real harm if successful.
Note: CISA has officially listed this as actively exploited in the wild. Treat it with higher urgency than usual.
What you should do: update the affected software to the latest version. If unsure, ask your IT team or search the vendor's site for "Microsoft Defender CVE-2026-45498".
CVE-2026-45498 (Microsoft Defender). Severity: Medium / CVSSv3 4.
Listed in CISA KEV — actively exploited in the wild. Patch as a top priority.
Response plan:
- Check the vendor advisory for affected versions and the patched release.
- If a vulnerable version is running in production, schedule maintenance (urgency from KEV/CVSS).
- If no patch yet, mitigate via WAF rule, disabling the affected feature, etc.
- Monitor logs / SIEM for known IOC and PoC signatures of this CVE.
PoCs and fix commits: see the 'References' section, MITRE, and NVD.
A weakness (CVE-2026-45498) in Microsoft Defender. A serious software flaw has been identified.
Target versions of Microsoft Defender (see vendor advisory). If running in production, identify exposure immediately.
Severity: Medium (CVSS 4/10). Exploitation requires specific conditions but can cause real harm if successful. Listed in CISA KEV (confirmed exploitation in the wild).
Update to the patched release as listed in the vendor advisory.
If a patch is not yet available, consider disabling the affected feature, applying WAF rules, blocking via network ACLs, or isolating the vulnerable version.
Check version information, scan dependencies via SBOM, and monitor SIEM for IOC and PoC signatures related to this CVE.
References
- advisory NVD
- advisory cisa.gov
- patch secure@microsoft.com
- web github.com