CVE-2025-33040: QNAP Systems Qsync Central · Unthrottled Resource Allocation
Affects QNAP Systems Qsync CentralSource CVE Database V5
Not known to be exploited · CVSS 7.1 High : upgrade to 5.0.0 soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 3 Oct 2025
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.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc. Qsync Central | Affected
| Fixed in
|
AI-suggested
European organizations should prioritize upgrading Qsync Central to version 5.0.0.1 or later to remediate this vulnerability. Beyond patching, organizations should implement strict user account management policies to reduce the risk of account compromise, including enforcing strong authentication mechanisms such as multi-factor authentication (MFA) for accessing Qsync Central. Monitoring and alerting on unusual resource consumption patterns within QNAP NAS devices can help detect exploitation attempts early. Network segmentation and access controls should be applied to limit exposure of Qsync Central services to only trusted networks and users. Regular audits of user accounts and permissions can reduce the attack surface. Additionally, organizations should maintain up-to-date backups of synchronized data to mitigate the impact of potential denial of service or other disruptions. Finally, security teams should stay informed on any emerging exploit developments related to this CVE to adjust defenses accordingly.
Description
An allocation of resources without limits or throttling vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to prevent other systems, applications, or processes from accessing the same type of resource. We have already fixed the vulnerability in the following version: Qsync Central 5.0.0.1 ( 2025/07/09 ) and later