CVE-2026-44656 in vim
Summary
by MITRE • 05/09/2026
Vim is an open source, command line text editor. Prior to version 9.2.0435, an OS command injection vulnerability exists in Vim's :find command-line completion. When the path option contains backtick-enclosed shell commands, those commands are executed during file name completion. Because the path option lacks the P_SECURE flag, it can be set from a modeline, allowing an attacker who controls the contents of a file to execute arbitrary shell commands when the user opens that file in Vim and triggers :find completion. This issue has been patched in version 9.2.0435.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 05/18/2026
The vulnerability in Vim's :find command-line completion represents a critical operating system command injection flaw that has existed in versions prior to 9.2.0435. This security weakness stems from the improper handling of shell command execution within the path option during file name completion operations. The vulnerability specifically manifests when the path option contains backtick-enclosed shell commands, which are then executed during the completion process without proper sanitization or security context validation. The fundamental technical flaw lies in the absence of the P_SECURE flag on the path option, which allows this parameter to be modified through vim modelines. This design oversight creates a dangerous attack vector where an attacker can embed malicious shell commands within a file's modeline, enabling arbitrary code execution when unsuspecting users open the file and subsequently trigger the :find completion functionality. The vulnerability operates under the principle of privilege escalation through file manipulation, where a user's normal file viewing activities become a vector for command execution.
The operational impact of this vulnerability extends far beyond simple code injection, as it represents a sophisticated attack pattern that can be leveraged in various real-world scenarios. When a user opens a malicious file containing a modeline with backtick-enclosed commands, the commands execute within the context of the user's privileges, potentially allowing attackers to escalate their access level or perform actions that would normally require elevated permissions. The vulnerability is particularly dangerous because it can be triggered automatically during normal file browsing operations, making it difficult for users to recognize when they are being targeted. This type of vulnerability aligns with CWE-78, which specifically addresses OS Command Injection, and demonstrates how seemingly innocuous configuration options can create significant security risks when not properly secured. The attack surface is expanded by the fact that modelines can be embedded in any text file, making this vulnerability particularly insidious as it can be exploited through various file types and delivery mechanisms.
Mitigation strategies for this vulnerability require both immediate patching and operational security enhancements. The most critical remediation is upgrading to Vim version 9.2.0435 or later, which implements proper security measures including the addition of the P_SECURE flag to prevent unauthorized modification of the path option through modelines. Organizations should also implement strict file access controls and educate users about the risks of opening untrusted files in text editors. Additional protective measures include disabling modeline processing entirely through vimrc configuration, implementing file type restrictions, and monitoring for suspicious file content patterns. From an ATT&CK framework perspective, this vulnerability maps to T1059.001 for Command and Scripting Interpreter, with potential lateral movement implications through command execution. Security teams should also consider implementing file integrity monitoring solutions that can detect unauthorized modifications to modelines or other embedded command structures. The vulnerability demonstrates the importance of principle of least privilege in software design, where configuration options should not be modifiable through user-controlled content without proper validation and security context checks.