Microsoft Office 2016: 14 Vulnerabilities Including RCE Flaws Disclosed Together
Microsoft Office 2016: 14 vulnerabilities, including high-severity flaws allowing code execution, disclosed together on August 11, 2026.
Key findings
- Microsoft Office 2016: 14 vulnerabilities disclosed on August 11, 2026.
- Batch includes multiple high-severity buffer overflow and integer underflow flaws enabling local code execution.
- Several medium-severity out-of-bounds read vulnerabilities allow for local information disclosure.
- All vulnerabilities were addressed in Microsoft's August 2026 Patch Tuesday update.
- No indication of in-the-wild exploitation for this specific batch of Office vulnerabilities.
On August 11, 2026, Microsoft released a significant batch of 14 vulnerabilities affecting Microsoft Office 2016 as part of its August Patch Tuesday. This coordinated disclosure event includes a mix of high and medium-severity flaws, with multiple vulnerabilities allowing for local code execution and information disclosure. The vulnerabilities were disclosed simultaneously, indicating a coordinated patch release by Microsoft.
Several vulnerabilities fall into common categories:
Buffer Overflows and Integer Underflows
Multiple high-severity vulnerabilities leverage buffer overflows and integer underflows to allow for local code execution. These include heap-based buffer overflows (CVE-2026-65661, CVE-2026-63533, CVE-2026-63513), stack-based buffer overflows (CVE-2026-63526), and integer overflows/underflows (CVE-2026-64909, CVE-2026-64903, CVE-2026-63532). These types of vulnerabilities can be exploited by an attacker to overwrite memory, potentially leading to arbitrary code execution.
Out-of-Bounds Reads
A significant number of medium-severity vulnerabilities are related to out-of-bounds reads, which can lead to local information disclosure. These include CVE-2026-68797, CVE-2026-64899, CVE-2026-63529, CVE-2026-63524, CVE-2026-63517, and CVE-2026-63515. An attacker exploiting these flaws could gain unauthorized access to sensitive information stored locally on the system.
Use of Uninitialized Resource
CVE-2026-70317, a medium-severity vulnerability, involves the use of an uninitialized resource, also leading to local information disclosure.
Exploitation and Response
While the provided CVEs themselves do not indicate active exploitation in the wild, related security advisories mention that Microsoft addressed a total of 415 or 421 vulnerabilities in its August 2026 security update release, with some advisories noting that one vulnerability (CVE-2026-68820, not part of this specific Office batch) was exploited in the wild. Microsoft has fixed all these vulnerabilities in its August 2026 Patch Tuesday release. Users are strongly advised to apply the latest security updates to mitigate these risks.
This batch of vulnerabilities underscores the importance of timely patching for Microsoft Office products. The presence of multiple high-severity flaws, particularly those allowing for code execution, necessitates prompt attention from users to protect their systems from potential compromise. Users should ensure their Office 2016 installations are up-to-date to benefit from the security fixes provided by Microsoft.
The vulnerabilities were disclosed on August 11, 2026.
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