🟠 High | Source: Microsoft Security Response Center
CVE-2026-55129 is a remote code execution vulnerability affecting Microsoft Office, meaning an attacker could potentially run malicious code on a victim’s machine by exploiting this flaw. The advisory acknowledgement has been updated, suggesting ongoing investigation or credit attribution rather than a new patch. Given the prevalence of Microsoft Office across enterprise environments, any RCE vulnerability in this suite carries significant risk.
Security Architect’s Take: Verify that the latest Microsoft Office patches are deployed across your organisation via your patch management tooling, and ensure Defender for Endpoint or equivalent EDR is active on endpoints where Office is in use. Monitor the MSRC advisory page for any patch or mitigation guidance updates.
Original advisory: CVE-2026-55129 Microsoft Office Remote Code Execution Vulnerability