Quick answers
- Is CVE-2026-81957 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-81957 being exploited in the wild.
- How severe is CVE-2026-81957?
- High severity, with a CVSS score of 7.8, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Excel.
- Is there a fix for CVE-2026-81957?
- 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-2026-81957 attacked?
- It is attacked with local access.
- Am I affected by CVE-2026-81957?
- 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
The vulnerability is an out-of-bounds read in Microsoft Excel that can be triggered when processing specially crafted spreadsheet files. An attacker can construct a malicious Excel file designed to read memory beyond the intended buffer boundaries, potentially exposing sensitive data or enabling code execution. The attack requires user interaction—a victim must open the malicious file—but no additional authentication is needed. Successful exploitation grants the attacker code execution in the context of the user running Excel. Microsoft has released patches to address this issue.
Affected products
- Microsoft Excel
Timeline
- 2026-09-08: disclosed