Microsoft Office Excel contains a remote code execution vulnerability that could allow an attacker to take complete control of an affected system if a user opens a specially crafted Excel file that includes a malformed object.

Microsoft Visual Basic for Applications (VBA) contains an insecure library loading vulnerability that could allow for remote code execution.

Microsoft Office Word contains a reliance on untrusted inputs in a security decision vulnerability that could allow an authorized attacker to elevate privileges locally.

Microsoft has published three out-of-band (OOB) updates so far in January 2026. One of these updates was released to address a vulnerability, CVE-2026-21509, affecting Microsoft Office that has been reportedly exploited in the wild.

Microsoft Office contains a security feature bypass vulnerability in which reliance on untrusted inputs in a security decision in Microsoft Office could allow an unauthorized attacker to bypass a security feature locally. Some of the impacted product(s) could be end-of-life (EoL) and/or end-of-service (EoS). Users are advised to discontinue use and/or transition to a supported version.

Microsoft Office PowerPoint contains a code injection vulnerability that allows remote attackers to execute arbitrary code via a PowerPoint file with an OutlineTextRefAtom containing an invalid index value that triggers memory corruption.