Microsoft Office buffer overflow

Summaryinfo

A vulnerability classified as critical has been found in Microsoft Office. Affected is an unknown function. The manipulation leads to buffer overflow. This vulnerability is documented as CVE-2026-63513. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Microsoft Office (version now known). This issue affects some unknown processing. 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-2026-63513 since 07/17/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. 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 08/11/2026).

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

• Office

License

• commercial

Website

• Vendor: https://www.microsoft.com/

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