Microsoft Excel Remote Code Execution Vulnerability
Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Published
- Jul 14, 2026
- Updated
- Sep 25, 2026
- EPSS
- 0.5% · 38th percentile
- CWE
- CWE-908
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · microsoft
- 7.8
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| microsoft | 365 apps | cpe:2.3:a:microsoft:365_apps |
| microsoft | excel | cpe:2.3:a:microsoft:excel |
| microsoft | microsoft 365 | cpe:2.3:a:microsoft:microsoft_365 |
| microsoft | office 2019 | cpe:2.3:a:microsoft:office_2019 |
| microsoft | office 2021 | cpe:2.3:a:microsoft:office_2021 |
| microsoft | office 2024 | cpe:2.3:a:microsoft:office_2024 |
| microsoft | office online server | cpe:2.3:a:microsoft:office_online_server |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- microsoft 365 appsall versions
- microsoft excel2016
- microsoft microsoft 365all versions
- microsoft office 2019all versions
- microsoft office 2021all versions
- microsoft office 2024all versions
- microsoft office online serverbefore 16.0.10417.20175
Versions reported by the vendor
Affected version ranges reported by the assigning authority (microsoft). Independent of NVD's CPE analysis and usually ahead of it.
Microsoft Microsoft 365 Apps for Enterprise
- 16.0.1 and later · before https://aka.ms/OfficeSecurityReleasesaffected
Microsoft Microsoft Excel 2016
- 16.0.0.0 and later · before 16.0.5561.1001affected
Microsoft Microsoft Office 2019
- 19.0.0 and later · before https://aka.ms/OfficeSecurityReleasesaffected
Microsoft Microsoft Office 365 for Mac
- 1.0.0 and later · before 16.111.26071215affected
Microsoft Microsoft Office LTSC 2021
- 16.0.1 and later · before https://aka.ms/OfficeSecurityReleasesaffected
Microsoft Microsoft Office LTSC 2024
- 16.0.0 and later · before https://aka.ms/OfficeSecurityReleasesaffected
Microsoft Microsoft Office LTSC for Mac 2021
- 16.0.1 and later · before 16.111.26071215affected
Microsoft Microsoft Office LTSC for Mac 2024
- 16.0.0 and later · before 16.111.26071215affected
Microsoft Office Online Server
- 16.0.0.0 and later · before 16.0.10417.20175affected
Same product
microsoft: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-23397Microsoft Outlook Elevation of Privilege VulnerabilityKEV98Now
- CVE-2024-21413Microsoft Outlook Remote Code Execution VulnerabilityKEV97Now
- CVE-2026-21509Microsoft Office Security Feature Bypass VulnerabilityKEV82Now
- CVE-2021-42292Microsoft Excel Security Feature Bypass VulnerabilityKEV74This week
- CVE-2023-35311Microsoft Outlook Security Feature Bypass VulnerabilityKEV70This week
- CVE-2024-38189Microsoft Project Remote Code Execution VulnerabilityKEV67This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Microsoft 365 Apps for Enterprise for 32-bit Systems | https://aka.ms/OfficeSecurityReleases · Click to Run | Microsoft (MSRC) |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | https://aka.ms/OfficeSecurityReleases · Click to Run | Microsoft (MSRC) |
| Microsoft Excel 2016 (32-bit edition) | 16.0.5561.1001 · KB5002886 | Microsoft (MSRC) |
| Microsoft Excel 2016 (64-bit edition) | 16.0.5561.1001 · KB5002886 | Microsoft (MSRC) |
| Microsoft Office 2019 for 32-bit editions | https://aka.ms/OfficeSecurityReleases · Click to Run | Microsoft (MSRC) |
| Microsoft Office 2019 for 64-bit editions | https://aka.ms/OfficeSecurityReleases · Click to Run | Microsoft (MSRC) |
| Microsoft Office 365 for Mac | 16.111.26071215 · Release Notes | Microsoft (MSRC) |
| Microsoft Office LTSC 2021 for 32-bit editions | https://aka.ms/OfficeSecurityReleases · Click to Run | Microsoft (MSRC) |
| Microsoft Office LTSC 2021 for 64-bit editions | https://aka.ms/OfficeSecurityReleases · Click to Run | Microsoft (MSRC) |
| Microsoft Office LTSC 2024 for 32-bit editions | https://aka.ms/OfficeSecurityReleases · Click to Run | Microsoft (MSRC) |
| Microsoft Office LTSC 2024 for 64-bit editions | https://aka.ms/OfficeSecurityReleases · Click to Run | Microsoft (MSRC) |
| Microsoft Office LTSC for Mac 2021 | 16.111.26071215 · Release Notes | Microsoft (MSRC) |
| Microsoft Office LTSC for Mac 2024 | 16.111.26071215 · Release Notes | Microsoft (MSRC) |
| Office Online Server | 16.0.10417.20175 · KB5002884 | Microsoft (MSRC) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-7851956 days apartMicrosoft Office Outlook Remote Code Execution Vulnerability35Monitor
- CVE-2025-53759336 days apartMicrosoft Excel Remote Code Execution Vulnerability31Monitor
- CVE-2026-8009156 days apartMicrosoft Office Information Disclosure Vulnerability26Monitor
- CVE-2026-550420 days apartMicrosoft Office Information Disclosure Vulnerability22Monitor
- CVE-2026-6879928 days apartMicrosoft Excel Information Disclosure Vulnerability22Monitor
- CVE-2026-7031728 days apartMicrosoft Office Information Disclosure Vulnerability22Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-908 · Use of Uninitialized ResourceCVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.