CVE-2025-33031: QNAP Systems File Station 5 · CWE-295
Affects QNAP Systems File Station 5Source CVE Database V5
Not known to be exploited · CVSS 8.3 High : upgrade to 5.6.0 soon.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.6.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Jun 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 2026-10-25.
What to do
Upgrade QNAP Systems File Station 5 to 5.6.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc. File Station 5 | Affected
| Fixed in
|
AI-suggested
European organizations should implement the following specific mitigation measures: 1) Immediately upgrade all affected QNAP File Station 5 installations to version 5.5.6.4847 or later to apply the official patch. 2) Enforce strong user authentication policies, including multi-factor authentication (MFA), to reduce the risk of initial account compromise. 3) Conduct regular audits of user accounts and permissions to ensure least privilege principles are maintained. 4) Monitor network traffic for unusual certificate validation failures or anomalies that could indicate attempted exploitation. 5) Segment NAS devices on isolated network zones with strict access controls to limit lateral movement opportunities. 6) Employ network intrusion detection/prevention systems (IDS/IPS) tuned to detect suspicious activity related to certificate misuse or MITM attempts. 7) Educate users on phishing and credential security to prevent account compromise. 8) Maintain up-to-date backups of critical data stored on NAS devices to enable recovery in case of compromise. These targeted actions go beyond generic advice by focusing on the specific attack vector and environment of QNAP File Station 5 deployments.
Description
An improper certificate validation vulnerability has been reported to affect File Station 5. If a remote attacker gains a user account, they can then exploit the vulnerability to compromise the security of the system. We have already fixed the vulnerability in the following version: File Station 5 5.5.6.4847 and later