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CVE-2025-30266VulnerabilityPublished

CVE-2025-30266: QNAP Systems Qsync Central · NULL Pointer Dereference

Affects QNAP Systems Qsync CentralSource CVE Database V5

0

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

CVSS 4.0 base score
0.6Low
How severe the flaw is on the 0–10 CVSS scale.
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:U

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Feb 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
QNAP Systems Inc.Qsync CentralAffected
  • =5.0.x.x
Fixed in
  • 5.0.0.4 ( 2026/01/20 )

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.

References

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