Quick answers
- Is CVE-2026-118717 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-118717 being exploited in the wild.
- How severe is CVE-2026-118717?
- High severity, with a CVSS score of 8.8, published 10 November 2026.
- Which products and versions are affected?
- Microsoft Excel.
- Is there a fix for CVE-2026-118717?
- 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-2026-118717 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-118717?
- Check whether you run Microsoft 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
A stack-based buffer overflow exists in Microsoft Excel's file parsing logic, allowing remote code execution via a crafted spreadsheet file. The vulnerability is triggered when a user opens a malicious Excel file, requiring user interaction but no authentication. An attacker can achieve arbitrary code execution with the privileges of the user running Excel.
Affected products
- Microsoft Excel
Timeline
- 2026-11-10: disclosed