CVE-2026-55132
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 · uneditedDouble free in Microsoft Office Word allows an unauthorized attacker to execute code locally.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- Microsoft CVE Summary - Bleeping Computer
Surfaced from public web coverage — external links open in a new tab.
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 double-free memory corruption vulnerability exists in Microsoft Office Word that allows an unauthenticated attacker to execute arbitrary code locally on the affected system. The double-free flaw occurs when memory is deallocated twice, potentially corrupting heap metadata and enabling control of program execution flow.
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 versionsall versionsall versionsall versionsall versions< 16.0.19725.20434= 2016= 2019= 2016CVSS 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 Word is installedOpen Word and go to File > Account, or check Add/Remove Programs in Windows Control Panel for Microsoft Office or Microsoft Word entriesAffected if Microsoft Word, Microsoft Office 2019, 2021, or 2024, or Microsoft 365 Apps are installed (all versions are affected)
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Determine Office version via Word applicationOpen Microsoft Word, go to File > Account > About Word. Note the version number shown (e.g., 16.0.xxxxx.xxxxx)Affected if Any version number is displayed, confirming Office/Word is installed (all versions affected per CVE)
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Check Office Click-to-Run version via registryOpen Registry Editor and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\Configuration, or HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\16.0\Common\InstallRoot for MSI installsAffected if Version key exists, indicating Office is installed (all versions affected)
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Verify SharePoint Server version if applicableCheck SharePoint version via Central Administration > System Settings > Manage servers in this farm, or run Get-SPProductVersion PowerShell cmdletAffected if SharePoint 2016, 2019, or versions earlier than build 16.0.19725.20434 are detected
If Microsoft Word, any Microsoft Office version (2019/2021/2024), Microsoft 365 Apps, or older SharePoint Server (2016/2019 or pre-build 19725) is installed, the system is affected by this double-free vulnerability.
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 · scoped16.0.19725.20434
Apply the latest Microsoft Office security updates to patched versions of Word. Prioritize patching systems running older, unsupported Office installations.
Microsoft 365/Office 365: Update to the latest version via Click-to-Run; Office 2016: Apply security update KBxxxxxx (refer to MSRC advisory); Office 2021/2024: Update to latest perpetual version
- Open Microsoft Word and go to File > Account > Update Options > Update Now to check for and install the latest Microsoft updates
- Alternatively, navigate to Microsoft Update Catalog (update.microsoft.com) and search for the specific security update for this CVE
- For enterprise environments, use Windows Server Update Services (WSUS) or Microsoft Configuration Manager to deploy the security update
- Ensure Microsoft Office is updated to a version that includes the security fix for this vulnerability
- After updating, verify the Office version by going to File > Account > About Word to confirm the installed version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 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 $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-55132 — 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-2026-55132 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