CVE-2025-53408Network attack vector

Authenticated denial of service via NULL dereference

Published Nov 7, 2025 · Updated Nov 7, 2025

NULL pointer dereference in QNAP File Station 5 5.5.x allows remote authenticated users to interrupt service through network requests. QNAP has not disclosed the affected request handler, the triggering input, or how processing that input produces the NULL pointer dereference. Access to any user account is required, and the published consequence is limited to availability without identifying a crash, hang, or broader system impact.

CVSS severity6.5
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in QNAP File Station 5 5.5.x allows remote authenticated users to interrupt service through network requests. QNAP has not disclosed the affected request handler, the triggering input, or how processing that input produces the NULL pointer dereference. Access to any user account is required, and the published consequence is limited to availability without identifying a crash, hang, or broader system impact.

The record

CVE
CVE-2025-53408
Published
Nov 7, 2025
Updated
Nov 7, 2025
Vendor
Linn Products Limited
Product
File Station 5
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.5.x <5.5.6.5018

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Linn Products Limited · File Station 5version=5.5.x <5.5.6.5018

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
1.3QNAP Systems, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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