Microsoft Office up to 16.108.26041219 heap-based overflow

Summaryinfo

A vulnerability classified as critical has been found in Microsoft Office. This impacts an unknown function. This manipulation causes heap-based overflow. The identification of this vulnerability is CVE-2026-42831. It is possible to initiate the attack remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Microsoft Office. It has been declared as critical. Affected by this vulnerability is some unknown processing. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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

The weakness was shared 05/12/2026 as confirmed security update guide (Website). The advisory is shared at msrc.microsoft.com. This vulnerability is known as CVE-2026-42831. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 05/19/2026).

Upgrading to version 16.109.26051019 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Office Suite Software

Vendor

• Microsoft

Name

• Office

Version

• -
• 0.37.3
• 9
• 10
• 10.0.8
• 14.3.2
• 16.0.5548.1000
• 16.0.5548.1001
• 16.0.5552.1002
• 16.0.10417.20113
• 16.0.10417.20128
• 16.108.26041219

License

• commercial

Website

• Vendor: https://www.microsoft.com/

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