QNAP
QNAP TS-251: active CVEs, secure or migrate
The QNAP TS-251 was targeted by ransomware campaigns (QLocker, DeadBolt) exploiting CVEs in QTS. The model remains usable with an up-to-date QTS and no Internet exposure.
- Risk level
- High risk
- Category
- NAS and storage
- Last reviewed
- 2026-05-23
- Confidence
- medium
Support status
Check the installed QTS version and consult QNAP security advisories for this model.
Typical symptoms
- Files encrypted with .deadbolt or .qlocker extension
- NAS exposed on public ports 8080/443
- QTS on old unpatched version
Fixes to try
- Update QTS immediately
- Disable port forwarding and use VPN
- Enable QNAP firewall and security notifications