What is CVE-2025-62459?

CVE-2025-62459 is a high-severity vulnerability in Microsoft 365 Defender Portal, classified under Cross-site Scripting. CVSS score: 8.3/10. Published 2025-11-20.

How severe is CVE-2025-62459?

High severity. CVSS v3 base score is 8.3 out of 10.

XSS in Microsoft 365 Defender Portal

CVE-2025-62459

Microsoft Defender Portal Spoofing Vulnerability

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.003 (22.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L.

Affected products

Microsoft 365_defender_portal
Microsoft 365 Defender Portal

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

secure@microsoft.com (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2025-62459?: CVE-2025-62459 is a high-severity vulnerability in Microsoft 365 Defender Portal, classified under Cross-site Scripting. CVSS score: 8.3/10. Published 2025-11-20.
How severe is CVE-2025-62459?: High severity. CVSS v3 base score is 8.3 out of 10.