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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 24 Mar 2022.
Office Compatibility PackApplication · Microsoft

CVE-2017-11826

HIGH · 7.8 CVSS v3.1 Published 2017-10-13
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
97/100
Remediation priority · Urgent
In the wild High EPSS Public exploit No privileges Patch available

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 · unedited
Microsoft Office 2010, SharePoint Enterprise Server 2010, SharePoint Server 2010, Web Applications, Office Web Apps Server 2010 and 2013, Word Viewer, Word 2007, 2010, 2013 and 2016, Word Automation Services, and Office Online Server allow remote code execution when the software fails to properly handle objects in memory.

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 confidence

Memory corruption vulnerability in Microsoft Office and Word products that fails to properly handle objects in memory, allowing remote code execution via specially crafted Office documents.

MitigationApply Microsoft security updates for affected Office products; avoid opening documents from untrusted sources.

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 data
Office Compatibility PackApplication
Affected:all versions
Office Online ServerApplication
Affected:= 2016
Office Web Apps ServerApplication
Affected:= 2010= 2013
Office Word ViewerApplication
Affected:all versions
Sharepoint Enterprise ServerApplication
Affected:= 2016
Sharepoint ServerApplication
Affected:= 2010= 2013
WordApplication
Affected:= 2007= 2010= 2013= 2016

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Microsoft Office products
    Open Control Panel > Programs and Features, look for Microsoft Office, Word, Office Compatibility Pack, Word Viewer, or Sharepoint Server installations. Alternatively, run 'Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Select-Object DisplayName, DisplayVersion' in PowerShell to list installed programs.
    Affected if Any of the following products are installed: Microsoft Office Compatibility Pack, Microsoft Office Online Server 2016, Microsoft Office Web Apps Server 2010 or 2013, Microsoft Office Word Viewer, Microsoft Sharepoint Enterprise Server 2016, Microsoft Sharepoint Server 2010 or 2013, Microsoft Word 20
  2. Determine the exact version of installed Microsoft Word
    Open Winword.exe (typically in C:\Program Files\Microsoft Office\root\Office16 or similar Office version folder), go to File > Account > About Word. Alternatively, right-click winword.exe in File Explorer, select Properties, and check the Details tab for version information.
    Affected if The version shown is 2007, 2010, 2013, or 2016 (specific build numbers within these versions would indicate vulnerability).
  3. Check for Office Compatibility Pack version
    Open Control Panel > Programs and Features, locate 'Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint Service Pack 3' or similar entry, and note the version. Alternatively, check file version of WLEXTCONV.DLL in the Office Compatibility Pack folder.
    Affected if Any version of Office Compatibility Pack is installed.
  4. Verify Word Viewer installation and version
    Open Control Panel > Programs and Features, look for 'Microsoft Office Word Viewer'. Check the installed version listed, or locate wordview.exe and check its file properties.
    Affected if Microsoft Office Word Viewer of any version is installed.
  5. Check Sharepoint Server version
    On the Sharepoint server, open Sharepoint Central Administration, go to 'Manage servers in this farm' to see the version. Alternatively, check the installed Sharepoint version via Programs and Features.
    Affected if Microsoft Sharepoint Server 2010, 2013, or Sharepoint Enterprise Server 2016 is installed.

Your environment is affected if any of the listed vulnerable Office products (Word 2007/2010/2013/2016, Office Compatibility Pack, Word Viewer, Sharepoint Server 2010/2013, or Sharepoint Enterprise Server 2016) are installed without the corresponding security update applied.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Patch available Apply the vendor patch
Vendor patch portal.msrc.microsoft.com →
Interim mitigation

Apply Microsoft security updates for affected Office products; avoid opening documents from untrusted sources.

Recommended fix High confidence

For Office Compatibility Pack and Word Viewer (all versions): Upgrade to a supported version of Microsoft Office. For Office Web Apps Server 2010: Upgrade to Office Web Apps Server 2013 or later. For SharePoint Server 2010 and 2013: Upgrade to SharePoint Server 2016 or SharePoint Server 2019.

  1. 1. Identify the specific affected Microsoft Office product installed (Word, Office Compatibility Pack, Word Viewer, SharePoint Server, Office Web Apps Server, or Office Online Server)
  2. 2. For Word 2016: Install KB4011212 from the November 2017 security update
  3. 3. For Word 2013: Install KB4011126 from the November 2017 security update
  4. 4. For Word 2010: Install KB4011120 from the November 2017 security update
  5. 5. For Word 2007: Install KB4011121 from the November 2017 security update
  6. 6. For Office Online Server 2016: Install KB4011178 from the November 2017 security update
  7. 7. For Office Web Apps Server 2013: Install KB4011136 from the November 2017 security update
  8. 8. For SharePoint Server 2010 (Word Automation Services): Install KB4011124 from the November 2017 security update
Caveat Patches are standard security updates with minimal risk; however, older products (Office Compatibility Pack, Word Viewer, Office Web Apps Server 2010, SharePoint Server 2010/2013) have reached end-of-support and should be upgraded to remain in supported states.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Office Compatibility Pack Exploited in the wild — priority engagement
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-11826 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

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.

What belongs here
  • 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