CVE-2026-55140

Microsoft Office Remote Code Execution Vulnerability

At a glance

Severity
HIGH 7.8
EPSS
EPSS 0.47 % · percentile 40 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
microsoft
NVD status
Analyzed

Description

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Cmicrosoft
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HNVD · secure@microsoft.com (Secondary)

Weaknesses (CWE)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Microsoft · Microsoft 365 Apps for Enterpriseaffected 16.0.1 < https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office 2016affected 16.0.0 < 16.0.5561.1000
Microsoft · Microsoft Office 2019affected 19.0.0 < https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office 365 for Macaffected 1.0.0 < 16.111.26071215
Microsoft · Microsoft Office LTSC 2021affected 16.0.1 < https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office LTSC 2024affected 16.0.0 < https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office LTSC for Mac 2021affected 16.0.1 < 16.111.26071215
Microsoft · Microsoft Office LTSC for Mac 2024affected 16.0.0 < 16.111.26071215

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD