CVE-2025-26642
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 · uneditedOut-of-bounds read in Microsoft Office 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 an out-of-bounds read vulnerability in Microsoft Office that allows an unauthorized local attacker to execute code. The vulnerability stems from improper bounds checking when Office processes certain data, potentially allowing an attacker to read memory beyond allocated buffers and leverage this for code execution.
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= 2016= 2016= 2019= 2021= 2024all versions= 2019CVSS 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 Microsoft Office productOpen any Office application (Excel, Access, Word), go to File > Account > About [App] to see the exact product and version installedAffected if The installed product matches any of the affected products listed (Microsoft 365 Apps, Access 2016, Excel 2016, Office 2016, Office 2019, Office LTSC 2021, Office LTSC 2024, Office Online Server, SharePoint Server 2019)
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Compare installed version against affected rangesNote the full version number from the About dialog and compare it to: Office 2016 (=version), Office 2019, Office LTSC 2021 (=version), Office LTSC 2024 (=version), or check if using Microsoft 365 Apps (all versions affected)Affected if The installed version matches or falls within any of the listed affected versions, or the product is Microsoft 365 Apps (all versions)
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Verify if Office processes documentsThis vulnerability triggers when Office processes data with improper bounds checking; any document opened, imported, or processed by the affected Office application could potentially trigger the vulnerable code pathAffected if The affected Office product is installed and processes documents or data files
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Confirm vulnerability context is presentThis is an out-of-bounds read flaw during Office data processing - the vulnerability exists in the core Office file parsing functionalityAffected if The affected Office product version is installed and can open or process document files
A user is affected if they have any of the listed Microsoft Office products installed with a version matching the affected ranges, particularly Office 2016, 2019, LTSC 2021, LTSC 2024, Microsoft 365 Apps, or Office Online Server, or SharePoint Server 2019.
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.
dbcve · scopedApply Microsoft security updates for Office immediately. Until patches are available, restrict local user privileges and exercise caution with Office documents from untrusted sources.
Microsoft has released patches for this vulnerability. Check Microsoft Update Catalog for KB articles corresponding to your affected product (Access, Excel, Office, Office Online Server, or SharePoint Server 2019). For Microsoft 365 Apps, ensure automatic updates are enabled or manually trigger an u
- Open Microsoft Outlook or any Microsoft Office application
- Go to File > Office Account > Update Options > Update Now
- Alternatively, check Windows Update (Settings > Windows Update > Check for updates)
- For enterprise deployments, deploy updates via Microsoft Update Catalog or WSUS
- Verify the update is installed by checking installed updates
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-26642 — 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-2025-26642 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