CVE-2025-62842
Published: 02 January 2026
Summary
CVE-2025-62842 is a high-severity External Control of File Name or Path (CWE-73) vulnerability in Qnap Hybrid Backup Sync. Its CVSS base score is 7.0 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 4.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2025-62842 is an external control of file name or path vulnerability (CWE-73) affecting HBS 3 Hybrid Backup Sync. Published on 2026-01-02, it has a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high impact on confidentiality, integrity, and availability with low attack complexity and privileges required.
An attacker with local network access and low privileges on the affected system can exploit this vulnerability to read or modify arbitrary files or directories, potentially leading to significant data compromise or system disruption.
QNAP's security advisory (QSA-25-46) states that the vulnerability has been fixed in HBS 3 Hybrid Backup Sync version 26.2.0.938 and later; users should update to a patched version for mitigation. Full details are available at https://www.qnap.com/en/security-advisory/qsa-25-46.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-0662
Vulnerability details
An external control of file name or path vulnerability has been reported to affect HBS 3 Hybrid Backup Sync. If an attacker gains local network access, they can then exploit the vulnerability to read or modify files or directories. We…
more
have already fixed the vulnerability in the following version: HBS 3 Hybrid Backup Sync 26.2.0.938 and later
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CWE-73 enables direct arbitrary local file read (T1005) and modification/deletion (T1565.001, T1070.004) on the affected system.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly prevents external control of file name or path by validating inputs to block path traversal attacks in HBS 3 Hybrid Backup Sync.
Addresses the specific flaw through timely patching to HBS 3 version 26.2.0.938 or later, eliminating the vulnerability as per QNAP advisory.
Limits damage from low-privilege exploitation by ensuring accounts have only necessary privileges to access files and directories.