QNAP Systems Qsync Central prior 5.0.0.4 null pointer dereference

HistoryDiffrelatejsonxmlCTI

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability was found in QNAP Systems Qsync Central and classified as problematic. Impacted is an unknown function. Such manipulation leads to null pointer dereference. This vulnerability is uniquely identified as CVE-2025-30266. The attack can be launched remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in QNAP Systems Qsync Central. It has been rated as problematic. Affected by this issue is an unknown code. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

A NULL pointer dereference vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to launch a denial-of-service (DoS) attack. We have already fixed the vulnerability in the following version: Qsync Central 5.0.0.4 ( 2026/01/20 ) and later

The weakness was disclosed by coral as qsa-26-02. The advisory is available at qnap.com. This vulnerability is handled as CVE-2025-30266 since 03/20/2025. The exploitation is known to be easy. The attack may be launched remotely. The technical details are unknown and an exploit is not available.

Upgrading to version 5.0.0.4 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

QNAP Systems

Name

Qsync Central

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Qsync Central 5.0.0.4

Timelineinfo

03/20/2025 CVE reserved
02/11/2026 +328 days Advisory disclosed
02/11/2026 +0 days VulDB entry created
02/12/2026 +1 days VulDB entry last update

Sourcesinfo

Advisory: qsa-26-02
Researcher: coral
Status: Confirmed

CVE: CVE-2025-30266 (🔒)
GCVE (CVE): GCVE-0-2025-30266
GCVE (VulDB): GCVE-100-345482

Entryinfo

Created: 02/11/2026 14:43
Updated: 02/12/2026 12:59
Changes: 02/11/2026 14:43 (68), 02/12/2026 12:59 (12)
Complete: 🔍
Cache ID: 216::103