CVE-2026-55439: Halo: Path Traversal in Backup Download Leads to Arbitrary File Read

Vulnerability summary

CVE-2026-55439 is a medium (CVSS 5.5) vulnerability in halo-dev halo. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 35.6% of scored vulnerabilities.

Timeline

1. 25-06-2026
   PublishedVulnerability first disclosed.
2. 25-06-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-22Improper Limitation of a Pathname to a Restricted DirectoryThe product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.