Use-after-free in Microsoft products - CVE-2026-45458

Vulnerability identifier: #VU134244

CSH Severity: High

CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-45458

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Microsoft Outlook and Word. A remote attacker can execute arbitrary code on the target system.

Microsoft SharePoint Server Subscription Edition
Microsoft SharePoint Enterprise Server
Microsoft SharePoint Server
Microsoft 365 Apps for Enterprise
Microsoft Office
Microsoft Word
Microsoft Office LTSC

Install updates from vendor's website.

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45458

• Multiple vulnerabilities in Microsoft Outlook and Word