CVE-2026-65656
Summary
by MITRE • 08/11/2026
Improper neutralization of special elements used in a command ('command injection') in Microsoft Office allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 08/11/2026
Command injection vulnerabilities in Microsoft Office represent a critical security risk that exploits improper handling of special elements within command execution contexts. This weakness allows attackers to inject malicious commands through Office applications, particularly when processing files or documents that contain crafted payloads designed to trigger system command execution. The vulnerability stems from insufficient input validation and sanitization mechanisms within Office's document processing pipelines, where user-controlled data is inadvertently passed to underlying system commands without proper neutralization. When Office applications process compromised documents containing malicious command sequences, the system executes these commands with the privileges of the executing user, potentially enabling arbitrary code execution on the target system.
The technical implementation of this vulnerability typically occurs when Microsoft Office applications handle file formats that support embedded scripts or external references. Attackers can craft specially formatted documents that contain command injection payloads designed to exploit specific Office components such as macros, embedded objects, or file processing routines. These payloads often leverage common shell commands or system utilities that are accessible through standard Office application interfaces. The flaw manifests when Office applications fail to properly sanitize user input or external data sources before incorporating them into system-level command invocations, creating opportunities for attackers to execute arbitrary code with the privileges of the compromised Office process.
From an operational perspective, this vulnerability enables attackers to establish persistent access and escalate privileges within compromised environments. Successful exploitation can result in full system compromise, data exfiltration, or lateral movement within network infrastructures. The local execution nature of this attack means that users must interact with malicious documents for exploitation to occur, making social engineering tactics such as phishing particularly effective. Attackers often leverage this vulnerability in targeted campaigns where they craft convincing documents designed to trigger the command injection when opened by unsuspecting users. The impact extends beyond individual system compromise, as compromised Office applications can serve as entry points for broader enterprise attacks.
Mitigation strategies for this vulnerability require a multi-layered approach combining application hardening, user education, and network security controls. Organizations should implement strict document validation policies that limit the execution of macros and external references within Office applications. Security patches from Microsoft should be applied promptly to address known command injection vulnerabilities in Office components. Network segmentation and firewall rules can help prevent unauthorized command execution attempts by restricting access to system utilities and command-line interfaces. Additionally, implementing application whitelisting solutions and configuring Office applications to run with minimal privileges can significantly reduce the potential impact of successful exploitation attempts.
This vulnerability aligns with CWE-77 and CWE-88 within the Common Weakness Enumeration framework, specifically addressing improper neutralization of special elements used in command contexts. The attack pattern corresponds to techniques documented in the MITRE ATT&CK framework under T1059.001 for Command and Scripting Interpreter, where adversaries leverage legitimate system utilities to execute malicious commands. Security professionals should monitor for indicators of compromise related to suspicious command execution patterns, anomalous network connections, and unexpected process creation events that may signal exploitation attempts. Regular security assessments and penetration testing can help identify potential attack vectors and validate the effectiveness of implemented mitigations against command injection vulnerabilities in Microsoft Office environments.