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Path TraversalWeakness · CWE-22

CVE-2026-55439

MEDIUM · 5.5 CVSS v3.1 Published 2026-06-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
61/100
Remediation priority · Elevated
Remotely reachable Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A path traversal vulnerability in Halo CMS allows authenticated administrators to read arbitrary files via the backup download endpoint (GET /apis/console.api.migration.halo.run/v1alpha1/backups/{name}/files/{filename}). The MigrationServiceImpl.download() method uses Path.resolve() without validating that the resolved path remains within the designated backups directory, enabling directory traversal attacks.

MitigationUpgrade to Halo version 2.24.3 or later, which includes proper path validation in the backup download endpoint and sanitization of status fields during backup creation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Halo CMS version
    Check the Halo application version through the admin console (usually displayed in the footer of the admin panel) or by inspecting the JAR/WAR file metadata if you have direct server access. Alternatively, query the API endpoint /api/v1alpha1/system if available, or check the startup logs for the version number.
    Affected if The installed version is lower than 2.24.3 (the fixed release).
  2. Verify backup/migration API endpoint accessibility
    Confirm that the endpoint /apis/console.api.migration.halo.run/v1alpha1/backups is accessible from your network. This can be tested by attempting a GET request to the base API path or reviewing your reverse proxy/web server configuration to confirm the route is not blocked.
    Affected if The migration API endpoint is reachable and the console API is enabled.
  3. Confirm administrator account existence
    Review the Halo user management panel to identify accounts with administrator privileges. The vulnerability requires an authenticated administrator session to exploit.
    Affected if There is at least one active administrator account configured in the system.
  4. Inspect access logs for suspicious backup file requests
    Review web server access logs (commonly found in /var/log/nginx/, /var/log/httpd/, or within the Halo data directory) for requests to /apis/console.api.migration.halo.run/v1alpha1/backups/*/files/* containing directory traversal patterns such as '../' or attempts to access files outside the intended backups directory.
    Affected if Log entries show requests to the backup download endpoint with traversal sequences or requests targeting sensitive system files.

You are affected if your Halo installation is version 2.24.2 or earlier, the console migration API is accessible, and an administrator account exists in the system.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to Halo version 2.24.3 or later, which includes proper path validation in the backup download endpoint and sanitization of status fields during backup creation.

Recommended fix High confidence

Halo version 2.24.3

  1. Stop the Halo application service to prevent active sessions during the upgrade
  2. Back up the current Halo installation and database according to your backup policy
  3. Download Halo version 2.24.3 from the official GitHub releases page (github.com/halo-dev/halo/releases)
  4. Replace the existing Halo installation files with the new version 2.24.3 files
  5. Start the Halo application service
  6. Verify the application starts successfully and the migration service is functional
  7. Confirm the vulnerability is resolved by attempting to access the backup endpoint (GET /apis/console.api.migration.halo.run/v1alpha1/backups/{name}/files/{filename}) and verifying it no longer allows path traversal
Caveat Review the Halo 2.24.3 release notes for any breaking changes between your current version and 2.24.3; minor version upgrades typically have minimal breaking changes but custom themes or plugins may need verification

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-55439 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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