CVE-2025-62858Network attack vector

Memory corruption and crashes via stack overflow

Published Jun 9, 2026 · Updated Jun 9, 2026

Stack-based buffer overflow in QNAP QTS and QuTS hero allows remote authenticated users to modify memory or crash processes. QNAP has not disclosed the affected component, attacker-controlled input, or operation that overruns the stack buffer. Exploitation requires an administrator account; the documented consequences are process-memory modification and process crashes, not code execution.

CVSS severity5.1
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in QNAP QTS and QuTS hero allows remote authenticated users to modify memory or crash processes. QNAP has not disclosed the affected component, attacker-controlled input, or operation that overruns the stack buffer. Exploitation requires an administrator account; the documented consequences are process-memory modification and process crashes, not code execution.

The record

CVE
CVE-2025-62858
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
Linn Products Limited
Product
QuTS hero
Classifications
CWE-121, T1499
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

6.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499Endpoint Denial of Service

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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