CVE-2026-88939 in Knowns
Summary
by MITRE • 09/10/2026
knowns through 0.33.0 exempts the project.set action from permission guard checks unconditionally, allowing read-only agent sessions to bypass restrictions. Attackers can invoke project.set to repoint the server at another project directory and obtain write access capabilities.
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Analysis
by VulDB Data Team • 09/10/2026
The vulnerability identified in versions of the software up through 0.33.0 represents a critical authentication and authorization failure within the application's core permission management system. Specifically, the flaw resides in how the backend handles the project.set action, which is designed to reconfigure or repoint the server instance toward a different project directory. Under normal operational parameters, this administrative function should be restricted to users with elevated privileges who have been explicitly granted write access rights. However, due to an unconditional exemption from permission guard checks, any session authenticated as read-only can invoke this action without triggering the necessary authorization validations. This architectural oversight effectively nullifies the security boundary between read-only and full-access user roles, creating a severe privilege escalation vector that undermines the integrity of the application's access control model.
From a technical perspective, the root cause is a logic error in the middleware or controller layer responsible for intercepting API requests before they reach the business logic handlers. The permission guard mechanism, which typically inspects the current user session and verifies their role against an allowlist or denylist of permitted actions, fails to execute its checks specifically for the project.set endpoint. By bypassing this gatekeeping step, a malicious actor operating with limited credentials can send a crafted request that instructs the server to change its working directory context. This action allows the attacker to shift the application's operational focus from a restricted environment to one where they possess write permissions or control over sensitive files and configurations. The ability to repoint the server at another project directory is particularly dangerous as it may expose internal data structures, configuration secrets, or other projects that were intended to remain isolated from lower-privileged users.
The operational impact of this vulnerability is significant, primarily centering on unauthorized access modification and potential remote code execution depending on how the application utilizes the target directory. An attacker can leverage this flaw to escalate their privileges from a passive observer to an active participant with write capabilities. This enables them to modify configuration files, inject malicious scripts, or alter data within the newly pointed project scope. In environments where multiple tenants share infrastructure, such as multi-tenant SaaS applications, this vulnerability could lead to cross-project data leakage or service disruption for other users. The lack of input validation on the target directory path further exacerbates the risk, potentially allowing attackers to traverse outside intended boundaries if symbolic links or relative paths are not strictly sanitized after the permission check is bypassed.
This flaw aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-269 Improper Privilege Management and CWE-862 Missing Authorization. The behavior also maps directly to techniques observed in the MITRE ATT&CK framework, specifically T1078 Valid Accounts for initial access or persistence, and potentially T1530 Data from Cloud Storage if the repointed directory contains sensitive cloud-backed resources. To mitigate this risk, developers must ensure that all administrative actions are subject to rigorous role-based access control checks regardless of their perceived sensitivity or historical exemption status. Implementing a default-deny policy for permission guards is essential, ensuring that no action bypasses validation unless explicitly and securely whitelisted with additional safeguards such as multi-factor authentication verification for high-risk operations. Furthermore, input sanitization should be applied to directory path arguments to prevent path traversal attacks once the authorization check has been successfully evaded.