Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from Vendor (qnap) · only source for this CVE.
CVSS VectorVendor: qnap
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
4DescriptionCVE.org
An incorrect authorization vulnerability has been reported to affect File Station 6. If a remote attacker gains a user account, they can then exploit the vulnerability to bypass intended access restrictions.
We have already fixed the vulnerability in the following version: File Station 5 5.5.6.5243 and later
AnalysisAI
Authorization bypass in QNAP File Station 5 (versions 5.5.0 through 5.5.6.5243) allows a remote attacker with a valid low-privileged user account to circumvent intended access restrictions and reach files or operations they should not be able to access. The flaw was reported by QNAP itself with a CVSS 4.0 score of 8.6 reflecting high confidentiality and integrity impact, and there is no public exploit identified at time of analysis. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires the attacker to already hold a valid authenticated user account on File Station 5 (CVSS PR:L), meaning any account that can log into the NAS web UI - including low-privileged or guest-level users - is sufficient; no admin role and no user interaction from a victim is needed. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 vector AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N indicates a network-reachable, low-complexity attack that requires only low-privileged credentials and no user interaction, yielding high confidentiality and integrity impact but no availability impact - consistent with an authorization bypass that exposes other users' files. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker obtains valid low-privileged File Station credentials on a target QNAP NAS - for example through credential stuffing against an internet-reachable NAS, a phished employee account, or abuse of a stale guest account. Authenticated as that user, the attacker sends crafted File Station requests that the application accepts despite the user lacking permission, allowing them to read, copy, or modify files belonging to other users or shares they should not reach. … |
| Remediation | Apply the vendor-released patch: upgrade File Station 5 to version 5.5.6.5243 or later via the QNAP App Center on each affected NAS, per QNAP advisory QSA-26-29 (https://www.qnap.com/en/security-advisory/qsa-26-29). … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
24 hours: Identify all QNAP File Station 5 deployments running versions 5.5.0-5.5.6.5243 and apply network-level access restrictions or enhanced monitoring. …
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-35980
GHSA-q4p9-vcgx-vmc3