Microsoft 365 Apps for Enterprise/Office buffer overflow

Summaryinfo

A vulnerability was found in Microsoft 365 Apps for Enterprise and Office. It has been classified as problematic. The affected element is an unknown function. The manipulation leads to buffer overflow. This vulnerability is uniquely identified as CVE-2026-65664. Local access is required to approach this attack. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Microsoft 365 Apps for Enterprise and Office (unknown version). This issue affects an unknown code block. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Impacted is 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 advisory is shared at msrc.microsoft.com. The identification of this vulnerability is CVE-2026-65664 since 07/22/2026. The exploitation is known to be easy. An attack has to be approached locally. 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 $0-$5k at the moment (estimation calculated on 08/12/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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

• 365 Apps for Enterprise
• Office

License

• commercial

Website

• Vendor: https://www.microsoft.com/

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