CVE-2025-54898
📋 TL;DR
This vulnerability allows an attacker to execute arbitrary code on a victim's system by exploiting an out-of-bounds read in Microsoft Excel. Attackers can achieve this by tricking users into opening a malicious Excel file. All users running vulnerable versions of Microsoft Excel are affected.
💻 Affected Systems
- Microsoft Excel
📦 What is this software?
365 Apps by Microsoft
365 Apps by Microsoft
Excel by Microsoft
Excel by Microsoft
Office by Microsoft
Office by Microsoft
Office Long Term Servicing Channel by Microsoft
View all CVEs affecting Office Long Term Servicing Channel →
Office Long Term Servicing Channel by Microsoft
View all CVEs affecting Office Long Term Servicing Channel →
Office Long Term Servicing Channel by Microsoft
View all CVEs affecting Office Long Term Servicing Channel →
Office Long Term Servicing Channel by Microsoft
View all CVEs affecting Office Long Term Servicing Channel →
Office Long Term Servicing Channel by Microsoft
View all CVEs affecting Office Long Term Servicing Channel →
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining complete control over the victim's computer, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local code execution with user privileges, allowing attackers to steal sensitive documents, install malware, or establish persistence on the compromised system.
If Mitigated
Limited impact with proper security controls like application sandboxing, macro restrictions, and user education preventing successful exploitation.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious file). No public exploit code is currently available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft's monthly security updates for specific version
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-54898
Restart Required: Yes
Instructions:
1. Open Microsoft Excel. 2. Go to File > Account > Update Options > Update Now. 3. Install all available updates. 4. Restart Excel and your computer if prompted.
🔧 Temporary Workarounds
Disable automatic opening of Excel files
windowsConfigure Excel to open files in Protected View by default
File > Options > Trust Center > Trust Center Settings > Protected View > Enable all Protected View options
Block Excel file attachments
allConfigure email gateways to block .xls, .xlsx, .xlsm attachments
🧯 If You Can't Patch
- Restrict Excel file execution to trusted sources only
- Implement application whitelisting to prevent unauthorized Excel execution
🔍 How to Verify
Check if Vulnerable:
Check Excel version against Microsoft's security bulletin for affected versionsCheck Version:
In Excel: File > Account > About ExcelVerify Fix Applied:
Verify Excel version is updated to latest security patch version📡 Detection & Monitoring
Log Indicators:
- Excel crash logs with memory access violations
- Unexpected Excel process spawning child processes
Network Indicators:
- Excel processes making unexpected network connections
SIEM Query:
process_name:"EXCEL.EXE" AND (event_id:1000 OR event_id:1001) AND description:"access violation"