CVE-2025-54166: QNAP Systems QTS · Out-of-bounds Read
Affects QNAP Systems QTSSource CVE Database V5
Not known to be exploited · CVSS 4.6 Medium : upgrade to 5.2.7.3256 build 20250913 when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.2.7.3256 build 20250913, h5.3.1.3250 build 20250912, h5.2.7.3256 build 20250913
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:UExploitation evidence
Disclosed: evidence found.
CVE published 2 Jan 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 QTS to 5.2.7.3256 build 20250913; QuTS hero to h5.3.1.3250 build 20250912 or h5.2.7.3256 build 20250913.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc.QTS | Affected
| Fixed in
|
| QNAP Systems Inc.QuTS hero | Affected
| Fixed in
|
AI-suggested
European organizations should immediately verify the QTS version running on their QNAP NAS devices and upgrade to the patched versions 5.2.7.3256 build 20250913 or later, or the corresponding QuTS hero versions. Since exploitation requires administrator privileges, organizations must enforce strong access controls, including multi-factor authentication (MFA) for all administrative accounts, and regularly audit administrator access logs for suspicious activity. Network segmentation should be implemented to limit exposure of NAS management interfaces to trusted internal networks only, reducing the attack surface. Employing intrusion detection systems (IDS) and endpoint detection and response (EDR) tools can help identify anomalous behavior indicative of credential compromise or exploitation attempts. Regularly updating firmware and software, combined with vulnerability scanning and penetration testing focused on NAS devices, will help maintain security posture. Additionally, organizations should ensure robust backup and recovery processes are in place to mitigate potential data loss from secondary attacks leveraging this vulnerability.
Description
An out-of-bounds read vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to obtain secret data. We have already fixed the vulnerability in the following versions: QTS 5.2.7.3256 build 20250913 and later QuTS hero h5.2.7.3256 build 20250913 and later QuTS hero h5.3.1.3250 build 20250912 and later