CVE-2026-55439 in halo
Summary
by MITRE • 06/25/2026
Halo is an open source website building tool. Prior to 2.24.3, a path traversal vulnerability in the backup download endpoint allows authenticated administrators to read arbitrary files from the server filesystem. The backup download endpoint (GET /apis/console.api.migration.halo.run/v1alpha1/backups/{name}/files/{filename}) in MigrationServiceImpl.download() resolves the backup filename via Path.resolve() without validating that the resolved path stays within the designated backups directory. Also, the Backup creation endpoint (POST /apis/migration.halo.run/v1alpha1/backups) does not sanitize the status fields during creation This vulnerability is fixed in 2.24.3.
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Analysis
by VulDB Data Team • 06/25/2026
The Halo website building tool presents a critical path traversal vulnerability that affects versions prior to 2.24.3, specifically within its migration service component. This flaw exists in the backup download endpoint which processes GET requests to retrieve backup files from the server filesystem. The vulnerability stems from insufficient input validation and path resolution mechanisms that fail to properly constrain file access within designated boundaries. Authentication requirements for exploitation mean that only administrators with valid credentials can leverage this vulnerability, though this does not mitigate the severity of potential impact.
The technical implementation of the flaw occurs in the MigrationServiceImpl.download() method where Path.resolve() is used without adequate sanitization or validation of the resolved path. This allows authenticated administrators to manipulate the filename parameter in the URL path to traverse directories outside of the intended backups directory. The vulnerability operates through a combination of inadequate path validation and improper boundary checking, creating an opportunity for arbitrary file reading from the server filesystem. The flaw is particularly concerning because it leverages legitimate administrative functionality to gain unauthorized access to system files that should remain protected.
This vulnerability directly maps to CWE-22 Path Traversal and aligns with ATT&CK technique T1078 Valid Accounts as it requires administrative privileges but enables unauthorized file access once those credentials are obtained. The operational impact of this vulnerability extends beyond simple information disclosure, potentially allowing attackers to access sensitive configuration files, database credentials, application source code, or other system artifacts that could facilitate further compromise. The attack surface is limited to authenticated administrators but represents a significant escalation of privileges within the application's security model.
The mitigation strategy involves upgrading to Halo version 2.24.3 which implements proper path validation and sanitization measures. Organizations should also conduct immediate security reviews to ensure no unauthorized access has occurred, verify that administrative accounts maintain appropriate least privilege access, and monitor for suspicious activities in backup operations. Additional defensive measures include implementing network segmentation, monitoring backup file access patterns, and ensuring proper input validation across all file handling endpoints. The fix demonstrates a proper remediation approach through comprehensive path validation and boundary checking that prevents directory traversal attacks at the code level.
The vulnerability highlights common security weaknesses in web application development practices where path resolution functions are used without proper sanitization or containment measures. This represents a failure to implement defense-in-depth principles around file system access controls and input validation. Organizations implementing similar backup or migration functionality should review their code for analogous path traversal vulnerabilities, particularly in endpoints that handle user-supplied filename parameters. The incident underscores the importance of automated security testing including static analysis and dynamic scanning to identify such vulnerabilities before they can be exploited in production environments.
Security teams should prioritize patching this vulnerability as it represents a direct pathway for attackers with administrative credentials to escalate their access and potentially compromise the entire application infrastructure. Regular security assessments of open source components are essential given that such vulnerabilities often remain undiscovered for extended periods in widely-used tools. The remediation process should include verification that all backup-related endpoints properly validate file paths and that no similar vulnerabilities exist in other areas of the application codebase.