QNAP Download Station: Path traversal allows reading unauthorized files
Summary
A relative path traversal vulnerability (CWE-23) in QNAP Download Station allows an authenticated remote attacker to read the contents of unexpected files or system data. The attacker must first obtain a valid Download Station user account. The CNA score is 8.7 (CVSS 4.0), but other sources score it lower, and the CNA title also mentions root RCE, which the description does not confirm.
Affected
- Download Station 5.10.x before 5.10.2.313
- Download Station 5.11.x before 5.11.3.322
- Branches older than 5.10: Unknown.
Fixed in
- Download Station 5.10.2.313 and later
- Download Station 5.11.3.322 and later
Workaround
- Unknown. QNAP lists no workaround. An unverified third-party source suggests disabling the vulnerable add-on or filtering the search parameter input.
Exploitation
- No evidence of exploitation in the wild found. CISA SSVC lists exploitation as none; the Strix page lists KEV as No.
- No public proof of concept found.
- Automatable: no (CISA SSVC).
Our recommendation
- Inventory QNAP NAS devices and check the Download Station version in the App Center.
- Update to 5.10.2.313 or 5.11.3.322 or later.
- Make sure the NAS is not reachable from the internet and review user accounts, including shared and former-staff accounts.
- Monitor the QNAP release notes for the QSA advisory and for clarification of the "Root RCE" title.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- QNAP Download Station release notes www.qnap.com
- CVE Program / CNA record via OpenCVE app.opencve.io
- Vulners VulnRichment CVE-2026-39993 vulners.com
- VulDB CVE-2026-39993 vuldb.com
- Strix CVE-2026-39993 www.strix.ai
- Positive Technologies PT-2026-114818 vulners.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 02:36.
Original description (NVD)
A relative path traversal vulnerability has been reported to affect Download Station. If a remote attacker gains a user account, they can then exploit the vulnerability to read the contents of unexpected files or system data. We have already fixed the vulnerability in the following version: Download Station 5.10.2.313 and later Download Station 5.11.3.322 and later
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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