Skip to main content
Mallory
High

Use-after-free in Microsoft Office

IdentifiersCVE-2026-45461CWE-416· Use After Free

CVE-2026-45461 is a critical memory-corruption vulnerability in Microsoft Office. The provided content consistently associates the flaw with a use-after-free condition in Office, while some summaries also describe the broader cluster as heap-based buffer overflows. Based on the more specific advisory language, the best-fit classification is a use-after-free vulnerability in Microsoft Office that can lead to local code execution. Microsoft notes that the Preview Pane is an attack vector, indicating that exploitation may be triggered during document rendering without requiring full manual opening of a malicious file in some scenarios. Successful exploitation results in attacker-controlled code execution in the context of the affected system.

Share:
For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

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. The advisory characterizes the impact as high across confidentiality, integrity, and availability. In practical terms, this can enable execution of malicious payloads in the user context, potentially leading to data theft, tampering, installation of additional malware, or further post-exploitation activity depending on the victim's privileges.

Mitigation

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

No vendor workaround is provided in the supplied content. Given Microsoft's note that the Preview Pane is an attack vector, defenders should reduce exposure by limiting or disabling preview/rendering of untrusted Office documents where operationally feasible, blocking or sandboxing untrusted attachments, restricting delivery of Office files from untrusted sources, and enforcing application control and least privilege until patches are fully deployed.

Remediation

Patch, then assume compromise.

Apply Microsoft's June 2026 security updates for affected Microsoft Office products. The provided advisory notes that updates for Microsoft Office LTSC for Mac 2021, Microsoft Office LTSC for Mac 2024, Microsoft 365 for Mac, and Microsoft Office for Android were not immediately available at publication time and would be announced in a future revision when released. Organizations should track MSRC release revisions and deploy the relevant Office updates as soon as they are available for each affected platform.
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 CorporationMicrosoft 365 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.