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Mallory
High

Use-after-free in Microsoft Office

IdentifiersCVE-2026-45474CWE-416· Use After Free

CVE-2026-45474 is a critical memory corruption vulnerability in Microsoft Office. The provided content consistently associates this CVE with a use-after-free condition in Office, although one source also generically describes it as a heap-based buffer overflow. The vulnerability affects Microsoft Office document handling/rendering and Microsoft advisory context indicates the Preview Pane is an attack vector, implying exploitation may occur during document preview or opening through Office/Word-based rendering paths. Successful exploitation can result in code execution on the affected system.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an unauthorized attacker to execute arbitrary code locally on the affected system in the security context of the user or process handling the malicious Office content. This can lead to compromise of confidentiality, integrity, and availability of the affected host.

Mitigation

If you can’t patch tonight, do this now.

Until patches are fully deployed, reduce exposure by avoiding previewing or opening untrusted Office documents, especially where the Preview Pane may invoke Office/Word rendering. Limit handling of untrusted files, enforce least-privilege for Office users, and prioritize patching exposed or high-risk endpoints once updates become available for each platform.

Remediation

Patch, then assume compromise.

Apply the Microsoft security update for affected Microsoft Office products. The provided advisory notes that updates for Microsoft Office LTSC for Mac 2021, 2024, Microsoft 365 for Mac, and Microsoft Office for Android were not immediately available at publication time and would be released later, so affected organizations should monitor Microsoft for revised releases and install platform-specific updates as they become available.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Microsoft Corporation365 Appsapplication
Microsoft Corporation365 For Macapplication
Microsoft CorporationOfficeapplication
Microsoft CorporationOffice 2016application
Microsoft CorporationOffice 2019application
Microsoft CorporationOffice 2021application
Microsoft CorporationOffice 2024application
Microsoft CorporationOffice 365application
Microsoft CorporationOffice Ltsc For Macapplication
Microsoft CorporationOffice Macos 2021application
Microsoft CorporationOffice Macos 2024application

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.