Vulnerability Database

383,304

Total vulnerabilities in the database

CVE-2025-53406 — qnap / qts

Use of Externally-Controlled Format String

A use of externally-controlled format string vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to obtain secret data or modify memory.

We have already fixed the vulnerability in the following versions: QTS 5.2.6.3195 build 20250715 and later QuTS hero h5.2.6.3195 build 20250715 and later

  • Published: Oct 3, 2025
  • Updated: Sep 13, 2026
  • CVE: CVE-2025-53406
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Medium
  • Score: 6.5
  • AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

CWEs:

Software Affected versions
qnap / qts = 5.2.0.2737-build_20240417
qnap / qts = 5.2.0.2744-build_20240424
qnap / qts = 5.2.0.2782-build_20240601
qnap / qts = 5.2.0.2802-build_20240620
qnap / qts = 5.2.0.2823-build_20240711
qnap / qts = 5.2.0.2851-build_20240808
qnap / qts = 5.2.0.2860-build_20240817
qnap / qts = 5.2.1.2930-build_20241025
qnap / qts = 5.2.2.2950-build_20241114
qnap / qts = 5.2.3.3006-build_20250108
qnap / qts = 5.2.4.3070-build_20250312
qnap / qts = 5.2.4.3079-build_20250321
qnap / qts = 5.2.4.3092-build_20250403
qnap / qts = 5.2.5.3145-build_20250526
qnap / quts_hero = h5.2.0.2737-build_20240417
qnap / quts_hero = h5.2.0.2782-build_20240601
qnap / quts_hero = h5.2.0.2789-build_20240607
qnap / quts_hero = h5.2.0.2802-build_20240620
qnap / quts_hero = h5.2.0.2823-build_20240711
qnap / quts_hero = h5.2.0.2851-build_20240808
qnap / quts_hero = h5.2.0.2860-build_20240817
qnap / quts_hero = h5.2.1.2929-build_20241025
qnap / quts_hero = h5.2.1.2940-build_20241105
qnap / quts_hero = h5.2.2.2952-build_20241116
qnap / quts_hero = h5.2.3.3006-build_20250108
qnap / quts_hero = h5.2.4.3070-build_20250312
qnap / quts_hero = h5.2.4.3079-build_20250321
qnap / quts_hero = h5.2.5.3138-build_20250519

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.