cve 2026 21258

CVE-2026-21258 is an information disclosure vulnerability affecting Microsoft Excel. Microsoft's security advisory confirms the vulnerability exists and recommends applying updates as the primary remediation. The public record is intentionally limited, omitting low-level exploit mechanics to reduce the risk of rapid weaponization. This tag covers discussions about the vulnerability's impact, patch guidance, and security implications for Excel users. Topics include Microsoft's advisory details, the importance of timely updates, and general information disclosure risks in Office products.