Vulnerability details
CVE-2026-55053
Microsoft 365 Apps for EnterpriseMicrosoft ExcelMicrosoft OfficeMicrosoft Office 365 for MacMicrosoft Office LTSCMicrosoft Office LTSC for Mac
Microsoft Excel Remote Code Execution Vulnerability
CVSS 3.1
7.8High
Official description
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.8High | 3.1 | CVEProject cvelistV5 (CNA) (microsoft) | 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 |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 ≤ v < https://aka.ms/OfficeSecurityReleases | CVEProject cvelistV5 (CNA) |
| Microsoft | Microsoft Excel 2016 | 16.0.0.0 ≤ v < 16.0.5561.1001 | CVEProject cvelistV5 (CNA) |
| Microsoft | Microsoft Office 2019 | 19.0.0 ≤ v < https://aka.ms/OfficeSecurityReleases | CVEProject cvelistV5 (CNA) |
| Microsoft | Microsoft Office 365 for Mac | 1.0.0 ≤ v < 16.111.26071215 | CVEProject cvelistV5 (CNA) |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 ≤ v < https://aka.ms/OfficeSecurityReleases | CVEProject cvelistV5 (CNA) |
| Microsoft | Microsoft Office LTSC 2024 | 16.0.0 ≤ v < https://aka.ms/OfficeSecurityReleases | CVEProject cvelistV5 (CNA) |
| Microsoft | Microsoft Office LTSC for Mac 2021 | 16.0.1 ≤ v < 16.111.26071215 | CVEProject cvelistV5 (CNA) |
| Microsoft | Microsoft Office LTSC for Mac 2024 | 16.0.0 ≤ v < 16.111.26071215 | CVEProject cvelistV5 (CNA) |
| Microsoft | Office Online Server | 16.0.0.0 ≤ v < 16.0.10417.20175 | CVEProject cvelistV5 (CNA) |
References and advisories
1- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55053 vendor-advisorypatch
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Details
- Published
- 2026-07-14
- Last updated
- 2026-11-01
- State
- Published
- Assigner (CNA)
- microsoft
Exploit prediction (EPSS)
0.46%
Probability of exploitation in 30 days
40.5%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-122Heap-based Buffer Overflow