Quick answers
- Is CVE-2026-44818 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-44818 being exploited in the wild.
- How severe is CVE-2026-44818?
- High severity, with a CVSS score of 7, published 9 June 2026.
- Which products and versions are affected?
- Microsoft Excel.
- Is there a fix for CVE-2026-44818?
- 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-2026-44818 attacked?
- It is attacked with local access, in a network appliance.
- Am I affected by CVE-2026-44818?
- 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
An integer underflow (wrap or wraparound) vulnerability exists within Microsoft Office Excel. The flaw is triggered when the application improperly handles specific data structures, leading to memory corruption. To exploit this, an attacker must rely on user interaction, typically by convincing a target to open a malicious Excel file. Successful exploitation allows for local code execution with the privileges of the logged-in user. Although the Microsoft advisory mentions CWE-362 (Race Condition), the primary description identifies an integer underflow as the root cause. The attack complexity is rated as high, suggesting specific timing or environmental conditions may be required for a successful exploit.
Affected products
- Microsoft Excel
Timeline
- 2026-06-09: advisory: Initial advisory published by Microsoft and NVD.