CVE-2026-65807

Microsoft Excel Remote Code Execution Vulnerability

At a glance

Severity: HIGH 8.8
EPSS: EPSS 0.82 % · percentile 57 (2026-10-27)
State: PUBLISHED
Published: 2026-08-11
Updated: 2026-10-21
Assigner: microsoft
NVD status: Analyzed

Description

Access of resource using incompatible type ('type confusion') in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C	microsoft
CVSS 3.1	HIGH 8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H	NVD · secure@microsoft.com (Secondary)

Weaknesses (CWE)

CWE-843

European references

ENISA EUVD · EUVD-2026-56445
GCVE · GCVE-0-2026-65807

CERT-FR advisories

CERTFR-2026-AVI-1000 — Multiples vulnérabilités dans Microsoft Office · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*
cpe:2.3:a:microsoft:excel:2016:*:*:*:*:*:x64:*
cpe:2.3:a:microsoft:excel:2016:*:*:*:*:*:x86:*
cpe:2.3:a:microsoft:microsoft_365:-:*:*:*:*:macos:*:*
cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x64:*
cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x86:*
cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:*
cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:*
cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:*
cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:*
cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:*
cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:*

Affected products

Product	Versions
Microsoft · Microsoft 365 Apps for Enterprise	affected 16.0.1 < https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Excel 2016	affected 16.0.0.0 < 16.0.5565.1001
Microsoft · Microsoft Office 2019	affected 19.0.0 < https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office 365 for Mac	affected 1.0.0 < 16.112.26081010
Microsoft · Microsoft Office LTSC 2021	affected 16.0.1 < https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office LTSC 2024	affected 16.0.0 < https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office LTSC for Mac 2021	affected 16.0.1 < 16.112.26081010
Microsoft · Microsoft Office LTSC for Mac 2024	affected 16.0.0 < 16.112.26081010
Microsoft · Office Online Server	affected 16.0.0.0 < 16.0.10417.20175

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65807

Sources

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