Overview
The vulnerability, identified as CVE-2025-54896, is a severe security risk present in Microsoft Office Excel. It allows an unauthorized attacker to execute code locally on the affected system, potentially leading to system compromise or sensitive data leakage. Given the widespread use of Microsoft Office Excel in both personal and professional environments, this vulnerability poses a significant threat to countless users worldwide.
Vulnerability Summary
CVE ID: CVE-2025-54896
Severity: High (7.8 CVSS score)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: System compromise and potential data leakage
Affected Products
    
      
    
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Product | Affected Versions
Microsoft Office Excel | All versions prior to the latest patch
How the Exploit Works
This vulnerability exploits a flaw in the memory management of Microsoft Office Excel. The issue is due to a use-after-free condition in the software, which means the software uses memory space after it’s been freed. As a result, an attacker can input malicious code which can then be executed by the software, allowing unauthorized access and potentially compromising the system or leaking sensitive data.
Conceptual Example Code
Consider a scenario where the attacker sends a specially crafted Excel file to the victim. The file contains malicious code that is executed once the file is opened in a vulnerable version of Excel. The code could look something like this:
=CALL("Kernel32","VirtualAlloc","JJJJJ",0,1000,4096,64)
=CALL("Kernel32","RtlMoveMemory","JJJCJ",return_value,"[malicious_code]",100)
=CALL("Kernel32","CreateThread","JJJJJJJJ",0,0,return_value,0,0,0,0)
=RETURN()
This is just a conceptual example, the actual exploit may be more complex and context-specific.
Mitigation Guidance
Users are strongly advised to apply the latest vendor patch from Microsoft. In the absence of an immediate patch, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. Security teams should also consider implementing strict controls on the opening of Excel files from untrusted sources.

