Use After Free in Microsoft 365_apps
CVE-2026-45458
Access of resource using incompatible type ('type confusion') in Microsoft Office allows an unauthorized attacker to execute code locally.
Vulnerability class: Use-After-Free
CVSS v3 metric
CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Microsoft 365_apps
- Microsoft Microsoft_365
- Microsoft Office_2019
- Microsoft Office_2021
- Microsoft Office_2024
- Microsoft Sharepoint_server — versions 2016, 2019
- Microsoft Word — versions 2016
Weakness classification (CWE)
References
- secure@microsoft.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-45458?
- CVE-2026-45458 is a high-severity vulnerability in Microsoft 365_apps, classified under Use After Free. CVSS score: 8.4/10. Published 2026-06-09.
- How severe is CVE-2026-45458?
- High severity. CVSS v3 base score is 8.4 out of 10.