VulnerabilityPublished 11 Feb 2026

CVE-2025-58471: QNAP Systems Qsync Central · Unthrottled Resource Allocation

Affects QNAP Systems Qsync CentralSource CVE Database V5

Not known to be exploited · CVSS 1.2 Low : upgrade to 5.2.0.1 ( 2025/12/21 ) when convenient.

Data as of 26 Oct 2026, 14:05 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 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.2.0.1 ( 2025/12/21 )

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 QNAP Systems Qsync Central to 5.2.0.1 ( 2025/12/21 ).

Affected software

Product	Affected	Fixed in
QNAP Systems Inc.Qsync Central	Affected =5.2.x.x	Fixed in 5.2.0.1 ( 2025/12/21 )

AI-suggested

Upgrade Qsync Central to version 5.2.0.1 or later immediately to apply the vendor's fix for this vulnerability.
Enforce strict administrative access controls and use multi-factor authentication to reduce the risk of credential compromise.
Monitor administrative account activities for unusual or excessive resource allocation patterns that could indicate exploitation attempts.
Implement resource usage monitoring and throttling policies at the system or network level to detect and prevent resource exhaustion scenarios.
Regularly audit and review user privileges to ensure that only necessary personnel have administrative rights.
Employ network segmentation to isolate critical NAS devices and limit exposure to potential attackers.
Maintain up-to-date backups to ensure data availability in case of service disruption.
Educate administrators about the risks of resource exhaustion vulnerabilities and the importance of timely patching.

Description

CVE-2025-58471 is a resource allocation vulnerability in QNAP Systems Inc. 's Qsync Central version 5.2.x.x. A remote attacker with administrator privileges can exploit this flaw to exhaust resources without limits or throttling, potentially denying access to those resources for other systems, applications, or processes. The vulnerability does not require user interaction and has a low CVSS score of 1.2, indicating limited impact and ease of exploitation. It has been fixed in Qsync Central version 5.2.

Impact

For European organizations, the impact of CVE-2025-58471 is generally low but not negligible. Organizations using Qsync Central 5.2.x.x in their NAS environments could experience denial of service conditions affecting file synchronization and sharing services if an attacker with administrative access exploits this vulnerability. This could disrupt business continuity, especially in sectors relying on QNAP NAS devices for critical data storage and collaboration, such as SMBs, educational institutions, and certain government agencies. The requirement for administrative privileges reduces the likelihood of exploitation by external attackers but raises concerns about insider threats or compromised administrator accounts. The denial of service caused by resource exhaustion could degrade system performance or availability, impacting productivity. However, since the vulnerability does not affect confidentiality or integrity directly, the risk of data breaches is minimal. Organizations with strong administrative access controls and monitoring are less likely to be impacted. The absence of known exploits in the wild further reduces immediate risk, but proactive patching is recommended to prevent future exploitation.

CWE-770Allocation of Resources Without Limits or Throttling (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #25
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Architecture and Design
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Exponential Data Expansion (opens in a new tab)
Serialized Data Parameter Blowup (opens in a new tab)
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

qnap.com/en/security-advisory/qsa-26-02 (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, 15:12 UTC

WeaknessesCWE-770

Technical details

References

Community reviews

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