CVE-2026-55439
CVE-2026-55439 is a medium-severity vulnerability with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.
Key facts
- Severity: Medium (CVSS 3.x base score 5.5)
- EPSS exploit prediction: 0% (26th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-39465
- Weakness: CWE-22
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-55439?
- 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.
- How severe is CVE-2026-55439?
- CVE-2026-55439 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability low.
- Is CVE-2026-55439 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-55439?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-55439 have an EU (EUVD) identifier?
- Yes. CVE-2026-55439 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39465.
- When was CVE-2026-55439 published?
- CVE-2026-55439 was published on 2026-06-25.
References
- https://github.com/halo-dev/halo/issues/10064
- https://github.com/halo-dev/halo/security/advisories/GHSA-h8wj-chr2-hf66
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