CVE-2025-30393
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 · high confidenceThis is a use-after-free memory corruption vulnerability in Microsoft Office Excel that allows an unauthorized attacker to execute arbitrary code locally on the affected system. The vulnerability stems from improper memory management in Excel's handling of certain objects or data structures, where memory is accessed after being freed, potentially leading to code execution in the context of the current user.
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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Verify Microsoft Excel is installedOpen Excel, go to File > Account > About Excel, or run 'winword --version' or check Programs and Features for Microsoft OfficeAffected if Excel is present on the system and the version falls within the affected ranges (Microsoft 365 Apps or Office LTSC 2021/2024)
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Determine the exact Office/Excel versionIn Excel, click File > Account > About Excel to see the version number (such as 16.0.xxxxx.xxxx for Microsoft 365) or check Help > About Microsoft ExcelAffected if Version is Microsoft 365 Apps (any version prior to the security update) or Office LTSC 2021/2024 without the CVE-2025-30393 patch
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Confirm the security update is appliedOpen Excel, go to File > Account > Check for Updates, or check Windows Update history for security update KB5062899 (or subsequent related update), or use 'Get-HotFix' in PowerShell to list installed updatesAffected if The specific KB5062899 (or subsequent CVE-2025-30393 security update) is NOT listed among installed updates
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Check for trusted document settings that may enable automatic executionIn Excel, go to File > Options > Trust Center > Trust Center Settings > Trusted Locations to identify where Excel files are opened fromAffected if Users routinely open Excel files from untrusted network locations or email attachments without validation
The environment is affected if Microsoft Excel (Microsoft 365 Apps or Office LTSC 2021/2024) is installed and the CVE-2025-30393 security update has not been applied.
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 Microsoft security update for CVE-2025-30393 to all affected Microsoft Office installations, prioritizing systems that handle untrusted Excel files. Verify the patch deployment and test Excel functionality to ensure compatibility.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 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 $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-30393 — 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-2025-30393 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