CVE-2026-54988: Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

PriorityP426medium6.1CVSS 3.1

AVLACLPRNUIRSUCLINAH

EPSS

0.31%

22.8th percentile

Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

Affected

11 ranges

Vendor	Product	Version range	Fixed in
microsoft	excel	—	—
microsoft	microsoft_365_apps_for_enterprise	>= 16.0.1 < https://aka.ms/OfficeSecurityReleases	https://aka.ms/OfficeSecurityReleases
microsoft	microsoft_excel_2016	>= 16.0.0.0 < 16.0.5561.1001	16.0.5561.1001
microsoft	microsoft_office_2019	>= 19.0.0 < https://aka.ms/OfficeSecurityReleases	https://aka.ms/OfficeSecurityReleases
microsoft	microsoft_office_365_for_mac	>= 1.0.0 < 16.111.26071215	16.111.26071215
microsoft	microsoft_office_ltsc_2021	>= 16.0.1 < https://aka.ms/OfficeSecurityReleases	https://aka.ms/OfficeSecurityReleases
microsoft	microsoft_office_ltsc_2024	>= 16.0.0 < https://aka.ms/OfficeSecurityReleases	https://aka.ms/OfficeSecurityReleases
microsoft	microsoft_office_ltsc_for_mac_2021	>= 16.0.1 < 16.111.26071215	16.111.26071215
microsoft	microsoft_office_ltsc_for_mac_2024	>= 16.0.0 < 16.111.26071215	16.111.26071215
microsoft	office_online_server	< 16.0.10417.20175	16.0.10417.20175
microsoft	office_online_server	>= 16.0.0.0 < 16.0.10417.20175	16.0.10417.20175

CVSS provenance

nvdv3.16.1MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

vendor_oracle9.8HIGH

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.