Quick answers
- Is CVE-2026-44817 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-44817 being exploited in the wild.
- How severe is CVE-2026-44817?
- High severity, with a CVSS score of 7.8, published 9 June 2026.
- Which products and versions are affected?
- Microsoft Excel.
- Is there a fix for CVE-2026-44817?
- 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-2026-44817 attacked?
- It is attacked with local access, in a network appliance.
- Am I affected by CVE-2026-44817?
- 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 (wraparound) vulnerability exists in Microsoft Office Excel. The flaw is triggered when the application processes a specially crafted file, leading to memory corruption or type confusion (CWE-843). While the attack vector is local, it requires user interaction, such as opening a malicious document. Successful exploitation allows an unauthenticated attacker to execute arbitrary code with the privileges of the current user. Microsoft has released security updates to address this issue.
Affected products
- Microsoft Excel
Timeline
- 2026-06-09: disclosed
- 2026-06-09: advisory