CVE-2025-30269: QNAP Systems Qsync Central · CWE-134
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, 14:05 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 25% 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 installations to version 5.0.0.4 or later, where the vulnerability is patched. In addition to patching, organizations should enforce strong user authentication policies, including multi-factor authentication (MFA), to reduce the risk of credential compromise. Regularly audit user accounts and permissions to ensure that only authorized personnel have access to Qsync Central. Implement network segmentation and access controls to limit exposure of Qsync Central services to trusted networks and users. Monitor logs for unusual activity indicative of exploitation attempts, such as unexpected format string errors or memory anomalies. Educate users on phishing and credential security to prevent account takeover. Finally, consider deploying application-layer firewalls or intrusion detection systems capable of detecting anomalous input patterns consistent with format string exploitation attempts.
Description
CVE-2025-30269 is a use of externally-controlled format string vulnerability in QNAP Systems Inc. 's Qsync Central product. A remote attacker with a valid user account can exploit this flaw to read secret data or modify memory, potentially leading to unauthorized information disclosure or application instability. The vulnerability affects Qsync Central versions 5.0.x.x prior to 5.0.0.4, which was patched in January 2026.