CVE-2026-55039
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk23th percentile - higher than 23% of all known CVEs
Summary
An integer underflow vulnerability in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Risk Assessment
An attacker could execute arbitrary code on the victim's machine, leading to full system compromise and potential data loss.
Recommendation
Immediately install the latest security updates for Microsoft Office Excel available through Microsoft Update.
Other vulnerabilities in Microsoft Office Excel
See all- CVE-2026-40360High
An out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
- CVE-2026-40359High
A use after free vulnerability in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- CVE-2026-20957High
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- CVE-2026-20956High
Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- CVE-2026-20955High
Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- CVE-2026-20950High
Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- CVE-2026-20949High
Improper access control in Microsoft Office Excel allows an unauthorized attacker to bypass a security feature locally.
- CVE-2026-20946High
An out-of-bounds read vulnerability in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- CVE-2026-70328Medium
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.
- CVE-2026-70327Medium
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.
Original NVD description (English source)
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.