Description
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
Published: 2026-07-14
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

An out‑of‑bounds read flaw in Microsoft Office Excel enables an unauthorized local user to read memory data that should be protected, allowing disclosure of potentially confidential information. The weakness is classified as CWE‑125, a buffer overread condition. As a result, an attacker with local access to a system can extract sensitive information from the process memory without triggering higher‑level permissions or remote code execution.

Affected Systems

Affected products include Microsoft 365 Apps for Enterprise, Microsoft Excel 2016, Office 2019, Office 2021 LTSC, Office 2024 LTSC, the Mac variants of Office 2021 and 2024, Office 365 for Mac, and the Office Online Server. These applications span both Windows and macOS environments, covering desktop and server deployments. No affected-version information is available in the CVE data.

Risk and Exploitability

The CVSS base score is 5.5, indicating moderate severity. The EPSS score falls below 1%, suggesting that exploitation is unlikely at present, and the vulnerability is not listed in the CISA KEV catalogue. The likely attack vector is local: an attacker must have access to the user session or device to trigger the read. Because the issue is an information‑disclosure bug, it does not grant arbitrary code execution, but it could expose sensitive data to local attackers.

Generated by OpenCVE AI on July 31, 2026 at 07:07 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Install the latest Microsoft Office security update for CVE‑2026‑50408, which is available through the Microsoft Security Update Guide.
  • Apply the cumulative update to all Microsoft 365 Apps, Office 2019, Office 2021 LTSC, Office 2024 LTSC, Office 365 for Mac, and the Office Online Server installations that include the fix.
  • As a temporary containment measure, limit or disable usage of the vulnerable Office applications on systems that cannot be patched immediately, thereby preventing local users from exploiting the flaw until an official patch is available.

Generated by OpenCVE AI on July 31, 2026 at 07:07 UTC.

Tracking

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Advisories

No advisories yet.

History

Thu, 16 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 15 Jul 2026 02:00:00 +0000

Type Values Removed Values Added
First Time appeared Microsoft office Online Server
Vendors & Products Microsoft office Online Server

Tue, 14 Jul 2026 17:45:00 +0000

Type Values Removed Values Added
Description Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
Title Microsoft Excel Information Disclosure Vulnerability
First Time appeared Microsoft
Microsoft 365 Apps
Microsoft excel 2016
Microsoft office 2019
Microsoft office 2021
Microsoft office 2024
Microsoft office 365
Microsoft office Macos 2021
Microsoft office Macos 2024
Weaknesses CWE-125
CPEs cpe:2.3:a:microsoft:365_apps:*:*:*:*:enterprise:*:*:*
cpe:2.3:a:microsoft:excel_2016:*:*:*:*:*:*:x86:*
cpe:2.3:a:microsoft:office_2019:*:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_2021:*:*:*:*:long_term_servicing_channel:*:*:*
cpe:2.3:a:microsoft:office_2021:*:*:*:*:ltsc:*:*:*
cpe:2.3:a:microsoft:office_2024:*:*:*:*:long_term_servicing_channel:*:*:*
cpe:2.3:a:microsoft:office_365:*:*:*:*:*:macos:*:*
cpe:2.3:a:microsoft:office_macos_2021:*:*:*:*:*:long_term_servicing_channel:*:*
cpe:2.3:a:microsoft:office_macos_2024:*:*:*:*:*:long_term_servicing_channel:*:*
Vendors & Products Microsoft
Microsoft 365 Apps
Microsoft excel 2016
Microsoft office 2019
Microsoft office 2021
Microsoft office 2024
Microsoft office 365
Microsoft office Macos 2021
Microsoft office Macos 2024
References
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C'}


Subscriptions

Microsoft 365 Apps Excel 2016 Office 2019 Office 2021 Office 2024 Office 365 Office Macos 2021 Office Macos 2024 Office Online Server
cve-icon MITRE

Status: PUBLISHED

Assigner: microsoft

Published:

Updated: 2026-08-03T22:56:52.613Z

Reserved: 2026-06-04T18:56:53.259Z

Link: CVE-2026-50408

cve-icon Vulnrichment

Updated: 2026-07-16T14:00:05.688Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-31T07:15:03Z

Weaknesses