CVE-2025-54899
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedFree of memory not on the heap in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA memory corruption vulnerability in Microsoft Office Excel allows an attacker to free memory not allocated on the heap, leading to arbitrary code execution. This is a local attack vector requiring the attacker to have access to the target system and induce the vulnerable code path in Excel.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versions= 2016= 2019= 2021= 2024CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed Excel versionOpen Excel, go to File > Account > About Excel. Alternatively, run 'winword.exe /?' or check Programs and Features in Control Panel for the Microsoft Office installation.Affected if The version is 2016, 2019, 2021, 2024, or any version of Microsoft 365 Apps (all versions are affected per the advisory)
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Confirm Excel is in useVerify that Microsoft Excel is installed and executable on the system by checking for the presence of Excel.exe in the Office installation directory (typically C:\Program Files\Microsoft Office\root\Office16 or similar).Affected if Excel is installed and available for use on the system
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Assess file handling exposureDetermine if the system processes Excel files from external or untrusted sources. Check recent Excel file openings or review email attachments, downloaded files, and network shares accessed by Excel.Affected if Users open Excel files from untrusted sources, as the vulnerability is triggered when Excel parses a specially crafted file
If the system runs Microsoft Excel version 2016, 2019, 2021, 2024, or any Microsoft 365 Apps version AND users can open Excel files, the environment falls within the affected scope and the vulnerability could be triggered.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply Microsoft security updates for Excel when released; until then, restrict access to untrusted Excel files, disable macros via group policy, and keep Office applications updated through organization's patch management.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-54899 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-54899 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data