Microsoft Office buffer overflow

Summaryinfo

A vulnerability was found in Microsoft Office and classified as problematic. This issue affects some unknown processing. Such manipulation leads to buffer overflow. This vulnerability is referenced as CVE-2026-63533. The attack can only be performed from a local environment. No exploit is available.

Detailsinfo

A vulnerability was found in Microsoft Office (the affected version is unknown). It has been rated as problematic. Affected by this issue is an unknown code. 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. CVE summarizes:

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

The advisory is shared for download at msrc.microsoft.com. This vulnerability is handled as CVE-2026-63533 since 07/17/2026. The exploitation is known to be easy. The attack needs to be approached locally. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/11/2026).

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

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Office Suite Software

Vendor

• Microsoft

Name

• Office

License

• commercial

Website

• Vendor: https://www.microsoft.com/

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