Microsoft Office Word heap-based overflow

Summaryinfo

A vulnerability, which was classified as critical, has been found in Microsoft Office. Affected by this issue is some unknown functionality of the component Word. This manipulation causes heap-based overflow. This vulnerability is tracked as CVE-2026-88186. The attack is possible to be carried out remotely. No exploit exists. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in Microsoft Office (affected version unknown). It has been declared as critical. Affected by this vulnerability is an unknown functionality of the component Word. 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 Word allows an unauthorized attacker to execute code over a network.

The advisory is shared at msrc.microsoft.com. This vulnerability is known as CVE-2026-88186 since 09/09/2026. 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 10/14/2026).

Applying a patch is able to eliminate this problem.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Office Suite Software

Vendor

• Microsoft

Name

• Office

License

• commercial

Website

• Vendor: https://www.microsoft.com/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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