Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

microsoft_office_for_mac july-14-2026: July 14, 2026

The Microsoft Office Online Server or Office Web Apps installation on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities:

  - Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
    (CVE-2026-47642, CVE-2026-54131, CVE-2026-55948)

  - Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to disclose     information locally. (CVE-2026-48580, CVE-2026-55138)

  - Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information     locally. (CVE-2026-50408, CVE-2026-54988, CVE-2026-55046, CVE-2026-55122, CVE-2026-55898)

  - Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code     locally. (CVE-2026-50675, CVE-2026-55029, CVE-2026-55037, CVE-2026-55041, CVE-2026-55053, CVE-2026-55131,     CVE-2026-55947, CVE-2026-58618)

  - Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to disclose     information locally. (CVE-2026-50678)

  - Access of resource using incompatible type ('type confusion') in Microsoft Office Excel allows an     unauthorized attacker to execute code locally. (CVE-2026-55024, CVE-2026-55025)

  - Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
    (CVE-2026-55031, CVE-2026-55044, CVE-2026-55058)

  - Buffer over-read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
    (CVE-2026-55036)

  - Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to     execute code locally. (CVE-2026-55039)

  - Integer overflow or wraparound in Microsoft Office Excel allows an unauthorized attacker to execute code     locally. (CVE-2026-55048)

  - Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over     a network. (CVE-2026-55054)

  - Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code     locally. (CVE-2026-55136)

  - Stack-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code     locally. (CVE-2026-55141, CVE-2026-55899)

  - Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to execute code     locally. (CVE-2026-55949)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Microsoft Excel Products are missing a security update. They are, therefore, affected by multiple vulnerabilities:

  - Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose     information over a network. (CVE-2026-55054)

  - Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute     code locally. (CVE-2026-50675, CVE-2026-55029, CVE-2026-55037, CVE-2026-55041, CVE-2026-55053,     CVE-2026-55131, CVE-2026-55137, CVE-2026-55947, CVE-2026-58618)

  - Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
    (CVE-2026-55948)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
326872	Security Updates for Microsoft Office Online Server (July 2026)	Nessus	Windows : Microsoft Bulletins	high
326860	Security Updates for Microsoft Excel Products (July 2026)	Nessus	Windows : Microsoft Bulletins	high

Detections

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CVE-2026-50675

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