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Microsoft Office Heap-Based Buffer Overflow RCE

IdentifiersCVE-2025-49697CWE-122· Heap-based Buffer Overflow

CVE-2025-49697 is a Microsoft Office remote code execution vulnerability caused by a heap-based buffer overflow. Microsoft classifies the weakness as CWE-122. The flaw affects Microsoft Office and was included in Microsoft’s July 2025 security updates. Microsoft states that successful exploitation allows an unauthorized attacker to execute code locally. Although the vulnerability is categorized as remote code execution, the published CVSS vector identifies a local attack vector (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), and Microsoft clarified that the term remote refers to the attacker’s location rather than a network-reachable service. Microsoft also states that the Preview Pane is an attack vector, indicating exploitation may be triggered through crafted Office content handled by Office rendering/parsing components.

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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 context of the affected system, with high impact to confidentiality, integrity, and availability. An attacker could potentially run malicious code without requiring privileges, leading to full compromise of the affected Office processing context and enabling follow-on actions such as data theft, document tampering, malware deployment, or disruption of system availability.

Mitigation

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

Until patches are fully deployed, reduce exposure to untrusted Office content. Avoid opening Office files from untrusted or unsolicited sources, use caution with files received by email or downloaded from websites, and limit reliance on the Preview Pane where operationally feasible because Microsoft identifies the Preview Pane as an attack vector. Prioritize mitigation and patching on systems that routinely process externally supplied Office documents.

Remediation

Patch, then assume compromise.

Apply all Microsoft-provided security updates for affected Microsoft Office products. Install all applicable updates offered for the affected software on the system; if multiple update packages apply, Microsoft states they may be installed in any order. Microsoft specifically noted that security updates for Microsoft Office LTSC for Mac 2021 and 2024 became available as of July 15, 2025, and those products should be updated 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 Corporation365 Copilotapplication
Microsoft CorporationOfficeapplication
Microsoft CorporationOffice 2016application
Microsoft CorporationOffice 2019application
Microsoft CorporationOffice 2021application
Microsoft CorporationOffice 2024application
Microsoft CorporationOffice Long Term Servicing Channelapplication
Microsoft CorporationOffice Macos 2021application
Microsoft CorporationOffice Macos 2024application
Microsoft CorporationOffice Online Serverapplication

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

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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.