CVE-2026-44822
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 Excel allows an unauthorized attacker to disclose information over a network.
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 Excel that allows an unauthorized remote attacker to read sensitive information from memory beyond the intended buffer boundaries. The network attack vector and CVSS score of 8.2 indicate significant risk of information disclosure without requiring user interaction beyond opening a malicious 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= 2016all versionsall versionsall versionsall versionsall versionsCVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
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.
-
Verify Excel is installedCheck for Excel executable (EXCEL.EXE) in typical installation paths such as C:\Program Files\Microsoft Office\root\Office16\ or C:\Program Files (x86)\Microsoft Office\root\Office16\, or query the Windows Registry under HKLM\SOFTWARE\Microsoft\Office\ClickToRun\Configuration or HKLM\SOFTWARE\Microsoft\Office\16.0\Common\InstallRootAffected if Excel executable is present on the system
-
Determine installed Excel versionRight-click EXCEL.EXE, select Properties, then view the Details tab for Product Version, or run 'winword /?' from command line if Office is in PATH, or check Registry key HKLM\SOFTWARE\Microsoft\Office\ClickToRun\Configuration for VersionToReportAffected if Version matches any of the affected products (Excel 2016, 2019, 2021, 2024, Microsoft 365 Apps, Office Online Server)
-
Check for pending Office security updatesOpen Excel, go to File > Account > Update Options > View Update History, or check Windows Update history for recent Microsoft Office security patchesAffected if No recent Excel-specific security updates installed or updates are disabled
-
Inspect Excel macro and external content settingsGo to Excel Options > Trust Center > Trust Center Settings > Macro Settings and External Content settings, or check Group Policy at Computer Configuration > Administrative Templates > Microsoft Office Excel > Security optionsAffected if Macro notifications are disabled or external content loading is automatically enabled without prompting
-
Review recent Excel file activityCheck Downloads folder, Outlook attachments folder, and browser download locations for newly downloaded .xlsx, .xlsm, .xls, .xlsb files, particularly from untrusted or unknown sourcesAffected if Unsolicited Excel files from unknown senders are present and may have been opened
If Microsoft Excel is installed and no specific security update for CVE-2026-44822 has been applied, the environment is vulnerable to out-of-bounds read attacks via malicious Excel files.
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 Microsoft security updates for Microsoft Office Excel as soon as they become available. Until a patch is released, restrict opening of untrusted Excel files from unknown sources and monitor for suspicious Office file activity.
- 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-2026-44822 — 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-2026-44822 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
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.
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