CVE-2025-66280: QNAP Systems QTS · Integer Overflow
Affects QNAP Systems QTSSource CVE Database V5
Not known to be exploited · CVSS 5.1 Medium : upgrade to 5.2.9.3410 build 20260214 when convenient.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.2.9.3410 build 20260214, h6.0.0.3397 build 20260206, h5.3.4.3500 build 20260520 +1
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Upgrade QTS to 5.2.9.3410 build 20260214; QuTS hero to h6.0.0.3397 build 20260206, h5.3.4.3500 build 20260520 or h5.2.9.3410 build 20260214.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc.QTS | Affected
| Fixed in
|
| QNAP Systems Inc.QuTS hero | Affected
| Fixed in
|
AI-suggested
The vulnerability has been fixed in QTS 5.2.9.3410 build 20260214 and later, and in the specified QuTS hero versions. Users should upgrade to these fixed versions to remediate the vulnerability. No additional mitigation guidance is provided or necessary beyond applying the official patches.
Description
An integer overflow or wraparound 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 compromise the security of the system. We have already fixed the vulnerability in the following versions: QTS 5.2.9.3410 build 20260214 and later QuTS hero h5.2.9.3410 build 20260214 and later QuTS hero h5.3.4.3500 build 20260520 and later QuTS hero h6.0.0.3397 build 20260206 and later