Quick answers
- Is CVE-2026-124183 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-124183 being exploited in the wild.
- How severe is CVE-2026-124183?
- 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-2026-124183?
- 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-2026-124183 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-124183?
- 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
A buffer over-read vulnerability exists in Microsoft Office Excel's file parsing logic, allowing an out-of-bounds memory read. An attacker can craft a malicious Excel file that, when opened, triggers the vulnerability to read adjacent memory and exfiltrate sensitive information over the network. No additional authentication or user interaction beyond opening the file is required.
Affected products
- Microsoft Office Excel
Timeline
- 2026-11-10: disclosed