VulnerabilityPublished 11 Feb 2026

CVE-2025-58466: QNAP Systems QTS · CWE-457

Affects QNAP Systems QTSSource CVE Database V5

Not known to be exploited · CVSS 1.2 Low : upgrade to 5.2.8.3332 build 20251128 when convenient.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score

1.2Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.2.8.3332 build 20251128, h5.2.8.3321 build 20251117

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: High
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: Unreported

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: High: The attacker requires privileges that provide significant (e.g., administrative) control over the vulnerable system allowing full access to the vulnerable system’s settings and files.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: Unreported: Based on threat intelligence sources each of the following must apply: · No knowledge of publicly available proof-of-concept · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade QTS to 5.2.8.3332 build 20251128; QuTS hero to h5.2.8.3321 build 20251117.

Affected software

Product	Affected	Fixed in
QNAP Systems Inc.QTS	Affected =>=5.2.0 <5.3.0	Fixed in 5.2.8.3332 build 20251128
QNAP Systems Inc.QuTS hero	Affected ≥ h5.2.x, < h5.2.8.3321 build 20251117	Fixed in h5.2.8.3321 build 20251117

AI-suggested

European organizations should immediately verify the QTS version running on their QNAP NAS devices and upgrade to QTS 5.2.8.3332 or later, or QuTS hero h5.2.8.3321 or later, as provided by QNAP. Since exploitation requires administrator privileges, organizations must enforce strong access controls, including multi-factor authentication (MFA) for all admin accounts, regular credential audits, and strict password policies. Network segmentation should be applied to isolate NAS devices from general user networks and limit remote administrative access to trusted IPs or VPNs. Continuous monitoring for unusual administrative activities and implementing intrusion detection systems can help detect potential exploitation attempts. Regular backups and disaster recovery plans should be tested to mitigate the impact of potential denial of service. Additionally, organizations should educate administrators on the risks of credential compromise and ensure timely patch management processes are in place to address future vulnerabilities promptly.

Description

CVE-2025-58466 is a low-severity vulnerability in QNAP's QTS operating system caused by the use of an uninitialized variable (CWE-457). It affects QTS version 5.2.x and allows a remote attacker with administrator privileges to cause denial of service or potentially alter control flow in unexpected ways. The vulnerability requires an attacker to already have admin-level access, does not require user interaction, and has no known exploits in the wild. QNAP has released fixes in QTS 5.2.8.3332 and later versions. While the CVSS score is low (1.

Impact

For European organizations, the impact primarily involves potential denial of service or system instability on QNAP NAS devices running vulnerable QTS versions. This could disrupt access to critical data and services hosted on these devices, affecting business continuity and operational efficiency. Since exploitation requires administrator access, the threat is heightened if credential compromise or insider threats occur. Industries relying heavily on NAS for data storage, such as finance, healthcare, and manufacturing, could face operational delays or data unavailability. Although the vulnerability does not directly lead to data breaches or privilege escalation, the denial of service could indirectly impact confidentiality and integrity by interrupting normal security monitoring or backup processes. The low CVSS score indicates limited direct risk, but the potential for unexpected control flow changes could introduce unknown risks if combined with other vulnerabilities or misconfigurations.

CWE-457Use of Uninitialized Variable (opens in a new tab)
Variant weaknessLikelihood of exploit: High
The code uses a variable that has not been initialized, leading to unpredictable or unintended results.
Implementation · Attack Surface Reduction
Ensure that critical variables are initialized before first use.
Build and Compilation · Compilation or Build Hardening
Most compilers will complain about the use of uninitialized variables if warnings are turned on.
Implementation · Operation
When using a language that does not require explicit declaration of variables, run or compile the software in a mode that reports undeclared or unknown variables. This may indicate the presence of a typographic error in the variable's name.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

qnap.com/en/security-advisory/qsa-26-05 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Feb 2026, 15:08 UTC

WeaknessesCWE-457

Technical details

References

Community reviews

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