CVE-2025-66280Network attack vector

Administrator-level service interruption via stack manipulation

Published Jun 10, 2026 · Updated Jun 10, 2026

Stack manipulation in QNAP QTS and QuTS hero allows remote authenticated users with administrator access to cause a service interruption. QNAP classifies the defect as integer overflow and stack-based buffer overflow, but has not disclosed the affected component, input field, or malformed value that triggers the stack manipulation. Exploitation requires an administrator account, and the disclosed consequences are unexpected system behavior or a denial-of-service condition rather than confidentiality loss.

CVSS severity7.2
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack manipulation in QNAP QTS and QuTS hero allows remote authenticated users with administrator access to cause a service interruption. QNAP classifies the defect as integer overflow and stack-based buffer overflow, but has not disclosed the affected component, input field, or malformed value that triggers the stack manipulation. Exploitation requires an administrator account, and the disclosed consequences are unexpected system behavior or a denial-of-service condition rather than confidentiality loss.

The record

CVE
CVE-2025-66280
Published
Jun 10, 2026
Updated
Jun 10, 2026
Vendor
Linn Products Limited
Product
QuTS hero
Classifications
CWE-190, CWE-121, T1499.004
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=h5.2.0 <h5.2.9.3410 build 20260214
  2. Affected versionversion=h5.3.0 <h5.3.4.3500 build 20260520
  3. Affected versionversion=? <h6.0.0.3397 build 20260206

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Linn Products Limited · QuTS heroversion=h5.2.0 <h5.2.9.3410 build 20260214; version=h5.3.0 <h5.3.4.3500 build 20260520; version=? <h6.0.0.3397 build 20260206
Linn Products Limited · QTSversion=5.2.0 <5.2.9.3410 build 20260214

Published CVSS scores

7.2National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
5.1QNAP Systems, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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