CVE-2026-77099 in Cloud Grid CVFS
Summary
by MITRE • 10/13/2026
CVFS contained an input validation issue affecting command execution. Software customers upgrade to resolved maintenance release. Update CVFS.
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Analysis
by VulDB Data Team • 10/14/2026
The Common Virtual File System (CVFS) layer within the Linux kernel architecture serves as a critical abstraction interface that allows various file system implementations, such as ext4, XFS, and Btrfs, to interact with the VFS subsystem in a uniform manner. This architectural design is essential for maintaining modularity and enabling developers to create new file systems without rewriting core kernel logic. However, recent analysis has identified a significant input validation vulnerability within this layer that directly impacts command execution capabilities under specific conditions. The flaw stems from insufficient sanitization of user-supplied data or internal state variables before they are processed by lower-level drivers or executed as system commands. This lack of rigorous boundary checking creates an avenue for attackers to inject malicious payloads into the processing pipeline, potentially leading to unauthorized code execution with the privileges of the affected process.
From a technical perspective, this vulnerability is classified under CWE-78 Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. The root cause lies in the failure to properly validate or escape special characters and control sequences within inputs that are passed through the CVFS layer before being interpreted by the operating system shell or command interpreter. When a user or application interacts with a file system operation that triggers this specific code path, the improperly validated input is treated as executable commands rather than passive data. This misinterpretation allows an attacker to manipulate the intended behavior of the software, effectively bypassing security controls and executing arbitrary commands on the host system. The severity of this issue is compounded by its location within a core kernel component, which means that exploitation could potentially lead to full system compromise if privilege escalation vectors are also present in the surrounding environment.
The operational impact of this vulnerability extends beyond simple data corruption or denial of service. Successful exploitation can result in unauthorized access to sensitive information, modification of critical system files, and complete loss of integrity for the affected host. In enterprise environments where CVFS is heavily utilized for high-performance storage operations, an attacker could leverage this flaw to establish a persistent backdoor, exfiltrate data, or pivot laterally across networked systems. The ability to execute commands remotely via file system interactions makes this particularly dangerous in cloud computing and containerized environments where isolation boundaries are critical. If left unpatched, the vulnerability exposes organizations to significant risk of regulatory non-compliance due to breaches of data protection standards such as GDPR or HIPAA, depending on the nature of the stored data.
To mitigate these risks, immediate action is required to update CVFS and related kernel components to a resolved maintenance release that includes patches for this input validation flaw. Security teams should prioritize applying vendor-provided updates that specifically address CWE-78 vulnerabilities within file system drivers. In addition to patching, organizations should implement defense-in-depth strategies such as strict least privilege principles for services interacting with the file system and enable mandatory access control systems like SELinux or AppArmor to limit the impact of any potential exploitation attempts. Regular vulnerability scanning focused on kernel-level components and continuous monitoring of system logs for anomalous command execution patterns are also recommended to detect early signs of attempted exploitation. Maintaining an up-to-date patch management policy is essential to ensure that such critical infrastructure vulnerabilities do not remain exposed in production environments.