CVE-2026-118727: Microsoft Office Excel out-of-bounds read

CVE-2026-118727 · Severity: medium · CVSS 6.5 · Published 2026-11-10

Microsoft Office Excel contains an out-of-bounds read vulnerability that allows an attacker to disclose sensitive information when a user opens a malicious spreadsheet file. An attacker could extract data from the application's memory, such as passwords, tokens, or other confidential information stored in the process, by crafting a specially designed Excel file.

Technologies: Microsoft Office Excel. Vendors: Microsoft.

Quick answers

Is CVE-2026-118727 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-118727 being exploited in the wild.
How severe is CVE-2026-118727?
Medium severity, with a CVSS score of 6.5, published 10 November 2026.
Which products and versions are affected?
Microsoft Office Excel.
Is there a fix for CVE-2026-118727?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-118727 attacked?
It is attacked over the network.
Am I affected by CVE-2026-118727?
Check whether you run Microsoft Office Excel. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An out-of-bounds read vulnerability exists in Microsoft Office Excel's file parsing logic, allowing an attacker to read memory regions outside the intended boundaries. The vulnerability requires user interaction (opening a malicious spreadsheet file) and network delivery of the payload. Successful exploitation discloses sensitive information from the Excel process memory without enabling code execution or denial of service.

Affected products

  • Microsoft Office Excel

Timeline

  • 2026-11-10: disclosed

References

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