What is CVE-2025-21364?

CVE-2025-21364 is a high-severity vulnerability in Microsoft 365_apps, classified under Deserialization of Untrusted Data. CVSS score: 7.8/10. Published 2025-01-14.

How severe is CVE-2025-21364?

High severity. CVSS v3 base score is 7.8 out of 10.

Deserialization in Microsoft 365_apps

CVE-2025-21364

Microsoft Excel Security Feature Bypass Vulnerability

Vulnerability class: Insecure Deserialization

EPSS: 0.016 (72.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Microsoft 365_apps
Microsoft 365 Apps For Enterprise — versions 16.0.1
Microsoft Office Ltsc 2024 — versions 16.0.0
Microsoft Office_long_term_servicing_channel — versions 2024

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

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

Frequently asked questions

What is CVE-2025-21364?: CVE-2025-21364 is a high-severity vulnerability in Microsoft 365_apps, classified under Deserialization of Untrusted Data. CVSS score: 7.8/10. Published 2025-01-14.
How severe is CVE-2025-21364?: High severity. CVSS v3 base score is 7.8 out of 10.