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Mallory
High

Use-After-Free RCE in Microsoft Office

IdentifiersCVE-2025-49699CWE-416· Use After Free

CVE-2025-49699 is a Microsoft Office remote code execution vulnerability caused by a use-after-free condition (CWE-416). Microsoft describes the issue as allowing an unauthorized attacker to execute code locally. Exploitation requires delivery of a malicious Office file to a target user and convincing that user to open it. Microsoft states the Preview Pane is not an attack vector for this vulnerability. The advisory characterizes the attack vector as local because the exploit is triggered on the victim system when the crafted file is opened, even though the attacker may be remote. Microsoft assigned CVSS 3.1 vector AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H and rated exploitation less likely.

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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 can result in arbitrary code execution in the security context of the local user who opens the malicious Office file. Given the CVSS impact metrics, compromise can have high confidentiality, integrity, and availability impact on the affected system and accessible data. No prior privileges are required, but execution is limited to the privileges of the victim user unless chained with additional vulnerabilities or misconfigurations.

Mitigation

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

No specific vendor workaround was provided. Practical mitigation includes preventing users from opening untrusted or unsolicited Office documents, enforcing file-origin protections and email/web content filtering for malicious Office attachments, and prioritizing patch deployment across affected Office installations. Because Microsoft states the Preview Pane is not an attack vector, disabling Preview Pane does not mitigate this issue.

Remediation

Patch, then assume compromise.

Apply the Microsoft security updates for all affected Office products. Where multiple update packages are offered for installed software, Microsoft advises installing all listed updates in any order. Microsoft also confirmed that security updates for Microsoft Office LTSC for Mac 2021 and 2024 became available as of 2025-07-15; those updates should be installed on affected Mac systems as well.
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 CorporationOfficeapplication
Microsoft CorporationOffice 2019application
Microsoft CorporationOffice 2021application
Microsoft CorporationOffice 2024application
Microsoft CorporationOffice Long Term Servicing Channelapplication
Microsoft CorporationOffice Macos 2021application
Microsoft CorporationOffice Macos 2024application
Microsoft CorporationOutlookapplication
Microsoft CorporationOutlook 2016application
Microsoft CorporationPowerpointapplication
Microsoft CorporationPowerpoint 2016application
Microsoft CorporationWordapplication
Microsoft CorporationWord 2016application

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.