QtsOperating system · Qnap

CVE-2025-62858

MEDIUM · 6.5 CVSS v3.1 Published 2026-06-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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
A buffer overflow vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to modify memory or crash processes. We have already fixed the vulnerability in the following versions: QTS 5.2.9.3410 build 20260214 and later QuTS hero h5.2.9.3410 build 20260214 and later QuTS hero h5.3.4.3500 build 20260520 and later QuTS hero h6.0.0.3397 build 20260206 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 · moderate confidence

Buffer overflow vulnerability in QNAP QTS and QuTS hero operating systems allowing a remote attacker who has obtained administrator credentials to modify memory or crash processes. The vulnerability has a CVSS score of 6.5 (MEDIUM) indicating significant but not critical impact.

MitigationApply available firmware updates (QTS 5.2.9.3410 build 20260214, QuTS hero h5.2.9.3410 build 20260214, h5.3.4.3500 build 20260520, or h6.0.0.3397 build 20260206) to affected devices. Additionally, enforce strict administrative credential controls and monitor for unauthorized admin account creation as the vulnerability requires admin-level access.

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
QtsOperating system
Affected:= 5.2.0.2737= 5.2.0.2744= 5.2.0.2782= 5.2.0.2802= 5.2.0.2823= 5.2.0.2851= 5.2.0.2860= 5.2.1.2930= 5.2.2.2950= 5.2.3.3006= 5.2.4.3070= 5.2.4.3079
Quts HeroOperating system
Affected:= h5.2.0.2737= h5.2.0.2782= h5.2.0.2789= h5.2.0.2802= h5.2.0.2823= h5.2.0.2851= h5.2.0.2860= h5.2.1.2929= h5.2.1.2940= h5.2.2.2952= h5.2.3.3006= h5.2.4.3070

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
None
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/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. Identify the QNAP OS product type
    Log into the QNAP admin console and check System Settings > About, or run 'getsysinfo' via SSH to determine if the system is running QTS or QuTS hero
    Affected if The system runs either QTS or QuTS hero firmware
  2. Check the installed firmware version
    Navigate to Control Panel > System > Firmware Update > About in the web interface, or run 'cat /etc/version' via SSH to retrieve the exact firmware build number
    Affected if The firmware version matches any of the listed affected builds
  3. Compare version against CVE affected list
    Match your installed version to the following affected builds - QTS: 5.2.0.2737, 5.2.0.2744, 5.2.0.2782, 5.2.0.2802, 5.2.0.2823, 5.2.0.2851, 5.2.0.2860, 5.2.1.2930, 5.2.2.2950, 5.2.3.3006, 5.2.4.3070, 5.2.4.3079 | QuTS hero: h5.2.0.2737, h5.2.0.2782, h5.2.0.2789, h5.2.0.2802, h5.2.0.2823, h5.2.0.2851, h5.2.0.2860, h5.2.1.2929, h5.2.1.2940, h5.2.2.2952, h5.2.3.3006, h5.2.4.3070
    Affected if The installed version exactly matches one of the versions in the affected list
  4. Verify administrative access controls
    Review administrator accounts in Control Panel > Security > Users, check for any unauthorized admin accounts or unexpected privilege escalations, and audit recent admin login activity from the Audit Log
    Affected if Any unauthorized administrator accounts exist or unexpected admin access has occurred

The system is affected if it runs QTS or QuTS hero firmware matching any of the specific build numbers listed in the CVE, and an attacker has already obtained administrative credentials.

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

Apply available firmware updates (QTS 5.2.9.3410 build 20260214, QuTS hero h5.2.9.3410 build 20260214, h5.3.4.3500 build 20260520, or h6.0.0.3397 build 20260206) to affected devices. Additionally, enforce strict administrative credential controls and monitor for unauthorized admin account creation as the vulnerability requires admin-level access.

Recommended fix High confidence

QTS 5.2.9.3410 build 20260214 or later; QuTS hero h5.2.9.3410 build 20260214 or later; QuTS hero h5.3.4.3500 build 20260520 or later; or QuTS hero h6.0.0.3399 build 20260206 or later (select based on product type)

  1. Identify the currently installed QTS or QuTS hero version via the QNAP admin interface (System Administration > Firmware Update)
  2. Determine the appropriate upgrade path based on current version and product type (QTS vs QuTS hero)
  3. Back up all critical data and configurations before performing the upgrade
  4. Access the QNAP admin interface and navigate to Control Panel > System Administration > Firmware Update
  5. Select "Check for Update" to download and install the appropriate fixed version: QTS 5.2.9.3410 (build 20260214 or later), QuTS hero h5.2.9.3410 (build 20260214 or later), QuTS hero h5.3.4.3500 (build 20260520 or later), or QuTS hero h6.0.0.3397 (build 20260206 or later)
  6. Verify the firmware update completes successfully and the system runs the fixed version
Caveat Standard QNAP firmware upgrade risks apply - ensure data backup before upgrading; some configurations may need reapplication after upgrade

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

Fix this in Qts Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2025-62858 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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