CVE-2026-87988 in Mistral Vibe
Summary
by MITRE • 09/11/2026
An arbitrary file access vulnerability in Mistral Vibe allows an attacker to bypass workspace restrictions through commands classified as unconditionally allowed. Missing path validation for these commands enables access to files outside the active workspace without user approval.
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Analysis
by VulDB Data Team • 09/11/2026
The identified flaw within the Mistral Vibe application represents a critical security deficiency centered on inadequate input validation and insufficient authorization controls regarding file system operations. This vulnerability, classified under CWE-22 as Improper Limitation of a Pathname to a Restricted Directory, allows an attacker to traverse outside the designated workspace boundaries. The core technical issue stems from the software's handling of specific commands that are categorized as unconditionally allowed by the application's security policy. Because these command categories bypass standard permission checks and user approval workflows, they serve as a direct vector for exploitation without requiring authentication or explicit consent from the system administrator or end-user.
From an operational perspective, this lack of path validation enables directory traversal attacks where malicious actors can construct file paths containing relative navigation sequences such as dot-dot-slash characters to escape the sandboxed environment. By leveraging these unconditionally permitted commands, an attacker gains read access to arbitrary files located on the host system or within other isolated workspaces that should remain inaccessible. This capability effectively neutralizes the intended isolation mechanisms of the application, transforming a contained workspace into a gateway for broader data exfiltration and sensitive information disclosure. The impact is severe as it compromises the confidentiality integrity of the entire deployment environment by exposing configuration files, credentials, source code, or personal data stored outside the active project directory.
This vulnerability aligns with MITRE ATT&CK technique T1083, which describes File and Directory Discovery, specifically when used to enumerate sensitive locations for subsequent exploitation. The absence of strict path canonicalization and boundary checks means that even if other security layers are in place, this specific entry point remains open due to the unconditional allowance of certain command types. Such a design flaw indicates a failure in implementing the principle of least privilege, where commands with high-impact side effects like file system access should require explicit validation against allowed directories rather than being granted blanket permission based on their classification alone.
To mitigate this risk, immediate remediation efforts must focus on enforcing strict path canonicalization for all file operations initiated through Mistral Vibe commands. Developers should implement a whitelist-based approach where only files explicitly located within the active workspace directory are accessible, rejecting any request that attempts to resolve to an external path regardless of the command type. Additionally, integrating robust input sanitization routines that detect and neutralize traversal sequences before they reach the file system API is essential. Security controls must be updated to ensure that even commands classified as unconditionally allowed undergo rigorous validation against workspace boundaries, thereby restoring the integrity of the isolation model and preventing unauthorized access to sensitive resources outside the designated scope.