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CVE-2025-62858 QNAP Systems Inc. CVE debrief

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. The vulnerability has already been fixed 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.

Vendor
QNAP Systems Inc.
Product
QTS
CVSS
MEDIUM 5.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-06-12
Advisory published
2026-06-09
Advisory updated
2026-06-12

Who should care

Administrators of QNAP operating systems, particularly those using versions prior to QTS 5.2.9.3410, QuTS hero h5.2.9.3410, QuTS hero h5.3.4.3500, and QuTS hero h6.0.0.3397, should apply the necessary patches to prevent exploitation.

Technical summary

The CVE-2025-62858 vulnerability is a buffer overflow issue with a CVSS score of 5.1 and a medium severity rating. It can be exploited by an attacker with high privileges (PR:H) over the network (AV:N) without requiring user interaction (UI:N). The vulnerability affects multiple versions of QNAP's QTS and QuTS hero operating systems.

Defensive priority

High

Recommended defensive actions

  • Apply patches: Upgrade to 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.
  • Restrict access: Limit administrator account access to only those who need it.
  • Monitor systems: Regularly monitor QNAP systems for suspicious activity.

Evidence notes

The information provided is based on the CVE-2025-62858 record and related sources.

Official resources

CVE-2025-62858 was published on 2026-06-09T08:16:26.503Z and modified on 2026-06-12T15:44:57.313Z.