CVE-2025-59243
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 · uneditedUse after free 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 confidenceThis is a use-after-free (UAF) memory corruption vulnerability in Microsoft Office Excel. A use-after-free occurs when a program continues to use memory after it has been freed, leading to unpredictable behavior that can be exploited to achieve arbitrary code execution. The attacker would need to entice a user to open a specially crafted malicious Excel file.
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= 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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Confirm Excel is installedOpen Microsoft Excel, go to File > Account > About Excel, or run 'excel --version' from Command Prompt/PowerShellAffected if Excel is not installed means not affected by this CVE
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Identify the Office installation typeOpen Excel, go to File > Account. Look for 'Microsoft 365' or check if it shows a version number like 'LTSC 2021' or 'LTSC 2024' under Office accountAffected if If it shows Microsoft 365 Apps (any version) or Office LTSC 2021 or LTSC 2024, the environment falls within affected product ranges
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Check Excel version numberIn Excel, go to File > Account > About Excel to see the exact version/build number, or run 'winword --version' which also displays Office version informationAffected if If the version is Microsoft 365 (any build) or matches Office LTSC 2021/2024, the environment is within the affected version ranges until patched
A system is affected if Microsoft Excel is installed and the installation type is Microsoft 365 Apps (any version) or Office LTSC 2021 or LTSC 2024, as all these versions are within the affected product ranges.
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 the relevant Microsoft security patch for CVE-2025-59243 as soon as it becomes available through Windows Update or the Microsoft Update Catalog. Until the patch is available, exercise caution with untrusted Excel files and consider disabling macros.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-59243 — 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-2025-59243 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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