CVE-2025-30266: QNAP Systems Qsync Central · NULL Pointer Dereference
Affects QNAP Systems Qsync CentralSource CVE Database V5
Not known to be exploited · CVSS 0.6 Low : upgrade to 5.0.0.4 ( 2026/01/20 ) when convenient.
Data as of 26 Oct 2026, 08:11 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.0.0.4 ( 2026/01/20 )
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:UExploitation 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.
What to do
Upgrade QNAP Systems Qsync Central to 5.0.0.4 ( 2026/01/20 ).
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc.Qsync Central | Affected
| Fixed in
|
AI-suggested
European organizations should immediately upgrade Qsync Central to version 5.0.0.4 or later to remediate the vulnerability. In addition to patching, organizations should enforce strong authentication mechanisms, such as multi-factor authentication (MFA), to reduce the risk of credential compromise. Regularly audit user accounts and remove or disable inactive or unnecessary accounts to minimize the attack surface. Network segmentation and firewall rules should restrict access to Qsync Central services to trusted networks and users only. Monitoring and logging of authentication attempts and service availability can help detect exploitation attempts or service disruptions early. Implementing rate limiting or anomaly detection on authentication endpoints can further mitigate brute force or credential stuffing attacks. Finally, organizations should maintain an incident response plan to quickly address potential denial-of-service incidents affecting critical services.
Description
CVE-2025-30266 is a NULL pointer dereference vulnerability in QNAP Systems Inc. 's Qsync Central version 5.0.x.x. A remote attacker with a valid user account can exploit this flaw to cause a denial-of-service (DoS) condition, crashing or disrupting the service. The vulnerability does not require user interaction but does require authenticated access, limiting the attack surface. The issue has been fixed in Qsync Central version 5.0.0.