Hybrid Backup SyncApplication · Qnap

CVE-2025-62842

HIGH · 7.8 CVSS v3.1 Published 2026-01-02
Fix available
A fix is available. Upgrade to 26.2.0.938 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

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
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 have already fixed the vulnerability in the following version: HBS 3 Hybrid Backup Sync 26.2.0.938 and later

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

This is a path traversal (external control of file name or path) vulnerability in QNAP's HBS 3 Hybrid Backup Sync application. An attacker with local network access can manipulate file paths in application requests to access files or directories outside the intended root directory, potentially reading or modifying sensitive data.

MitigationApply the vendor patch by upgrading HBS 3 Hybrid Backup Sync to version 26.2.0.938 or later. Restrict network access to trusted users as an additional layer of defense.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Hybrid Backup SyncApplication
Affected:< 26.2.0.938

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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. Confirm HBS 3 Hybrid Backup Sync is installed
    Locate the Hybrid Backup Sync application on the QNAP system via the App Center or by checking for the HBS 3 process/service
    Affected if HBS 3 Hybrid Backup Sync is not present on the system, the vulnerability does not apply
  2. Identify installed HBS 3 version
    Access the QNAP App Center, click on Hybrid Backup Sync, and view the installed version number displayed in the application details
    Affected if The displayed version number is below 26.2.0.938
  3. Verify version via command line (if available)
    Use the QNAP CLI or check the package manifest if SSH access is available to retrieve the exact HBS 3 version string
    Affected if The version retrieved is lower than 26.2.0.938
  4. Confirm network accessibility of HBS 3
    Check if the HBS 3 web interface or backup services are accessible from the local network, as the vulnerability requires local network access to exploit
    Affected if HBS 3 services are exposed on the network and the version is below 26.2.0.938

User is affected if HBS 3 Hybrid Backup Sync is installed and the installed version is lower than 26.2.0.938, regardless of network accessibility since the vulnerable code is present locally.

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
Upgrade available Upgrade to 26.2.0.938 or later
Fixed in 26.2.0.938
Interim mitigation

Apply the vendor patch by upgrading HBS 3 Hybrid Backup Sync to version 26.2.0.938 or later. Restrict network access to trusted users as an additional layer of defense.

Recommended fix High confidence

HBS 3 Hybrid Backup Sync 26.2.0.938 or later

  1. Access the QNAP NAS admin interface (QTS)
  2. Navigate to App Center
  3. Locate HBS 3 Hybrid Backup Sync in the installed applications
  4. Update HBS 3 Hybrid Backup Sync to version 26.2.0.938 or later
  5. Verify the update was successful by checking the installed version

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

Fix this in Hybrid Backup Sync Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.

Scan for this in your stack

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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-2025-62842 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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data