CVE-2026-78511: Microsoft Office Word Remote Code Execution Vulnerability
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Other sources
Microsoft Office Word Remote Code Execution Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.5569.1000Patch KB5002923 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.17932.20960 - Upgrade
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Fixed in 16.0.14334.20896 - Upgrade
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Fixed in 16.0.10417.20204 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.20326.20136
Event History
Frequently Asked Questions
Does exploitation require attacker credentials or user interaction?
The CVSS vector indicates no privileges are required (PR:N), but user interaction is required (UI:R). The attack vector is network-based (AV:N) and has low attack complexity (AC:L).
Which Word deployments are listed as affected?
The affected software list includes Word 2016, Microsoft 365 Apps for Enterprise, Office 365 for Mac, Office LTSC 2021 for 64-bit editions, Office LTSC 2024 for 32-bit and 64-bit editions, and Office LTSC for Mac 2021 and 2024.
What could an attacker achieve if exploitation succeeds?
The CVSS metrics rate confidentiality, integrity, and availability impact as high. Successful exploitation can therefore result in high impact to all three security properties.