CVE-2026-56193 Microsoft CVE debrief

Who should care

Organizations using Microsoft Office, particularly those with high security requirements, should be aware of this vulnerability and take steps to mitigate it.

Technical summary

CVE-2026-56193 is an out-of-bounds read vulnerability in Microsoft Office that allows an unauthorized attacker to disclose information locally. The vulnerability has a CVSS score of 7.1 and is classified as HIGH severity. It affects various versions of Microsoft Office, including Office 2016, Office 2019, Office 2021, and Office 2024.

Defensive priority

High priority should be given to patching vulnerable systems, as this vulnerability could allow an attacker to disclose sensitive information.

Recommended defensive actions

• Apply patches or updates provided by Microsoft to vulnerable systems
• Conduct a thorough inventory of Microsoft Office installations to identify potentially vulnerable systems
• Implement compensating controls, such as monitoring for suspicious activity, until patches can be applied
• Consider isolating or restricting access to sensitive information and systems

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further investigation and testing may be necessary to fully understand the impact and potential mitigations.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.