CVE-2023-39296Network attack vector

Unauthenticated NAS crash via prototype pollution

Published Jan 5, 2024 · Updated Jun 3, 2025

Prototype pollution in QNAP QTS 5.1.x and QuTS hero h5.1.x allows remote attackers to crash a NAS through network requests. User-controlled input overrides existing object attributes with incompatible values, but QNAP has not disclosed the affected component or request field. Unauthenticated network access is sufficient, and successful exploitation interrupts availability without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability1.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in QNAP QTS 5.1.x and QuTS hero h5.1.x allows remote attackers to crash a NAS through network requests. User-controlled input overrides existing object attributes with incompatible values, but QNAP has not disclosed the affected component or request field. Unauthenticated network access is sufficient, and successful exploitation interrupts availability without reported data disclosure or modification.

The record

CVE
CVE-2023-39296
Published
Jan 5, 2024
Updated
Jun 3, 2025
Vendor
Linn Products Limited
Product
QuTS hero
Classifications
CWE-1321, CAPEC-77, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 5, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2025Record 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=h5.1.x <h5.1.3.2578 build 20231110

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Linn Products Limited · QuTS heroversion=h5.1.x <h5.1.3.2578 build 20231110
Linn Products Limited · QTSversion=5.1.x <5.1.3.2578 build 20231110

Published CVSS scores

7.5QNAP Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
CAPEC-77Manipulating User-Controlled Variables
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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