Threat Intelligence / CVE / CVE-2025-66273

CVE-2025-66273 — QNAP Systems Inc. QTS

CVSS v3.1 7.2 (HIGH) · CVSS v4.0 8.6 · EPSS 0.9% (higher than 57.0% of all scored CVEs) · Priority 5.9/10 · Published 2026-06-10

As of 2026-06-11, CVE-2025-66273 is a HIGH-severity vulnerability in QNAP Systems Inc. QTS, CVSS v3.1 7.2, EPSS 0.9% (57.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2025-66273, most recently “QNAP QSA-26-10: Multiple Injection and Memory-Safety Vulnerabilities in QTS, QuTS hero, QuTS cloud, QVP, and File Station (CVE-2025-66273, CVE-2026-26240, and 12 others)”.

Last updated: 2026-06-11

What is CVE-2025-66273?

A command injection 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 execute arbitrary commands. We have already fixed the vulnerability in the following versions: QTS 5.2.9.3410 build 20260214 and later QuTS hero h5.2.9.3410 build 20260214 and later QuTS hero h5.3.4.3500 build 20260520 and later QuTS hero h6.0.0.3397 build 20260206 and later

The record classifies CVE-2025-66273 under weakness class CWE-78. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs high-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 94 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 7.2 — HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0 base score: 8.6
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS (FIRST): 0.9% probability of exploitation in the next 30 days, higher than 57.0% of all scored CVEs
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 5.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2026-06-10, last modified 2026-06-11

Is CVE-2025-66273 being exploited?

No public exploitation evidence for CVE-2025-66273 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-06-11. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

Affected products and versions

QNAP Systems Inc.: QTS, QuTS hero

How to fix CVE-2025-66273

Vendor advisory: https://www.qnap.com/en/security-advisory/qsa-26-10. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2025-66273

1 tracked threat in the Threadlinqs corpus references CVE-2025-66273, either in the campaign’s CVE list or as an indicator on the campaign record.

QNAP QSA-26-10: Multiple Injection and Memory-Safety Vulnerabilities in QTS, QuTS hero, QuTS cloud, QVP, and File Station (CVE-2025-66273, CVE-2026-26240, and 12 others) — HIGH · 2026-06-22

Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-06-22. This product uses the NVD API but is not endorsed or certified by the NVD.

Other references

qnap.com

Full detection coverage & IOCs for threats exploiting CVE-2025-66273 are available via the Threadlinqs MCP server (Purple tier). View plans →

← all vulnerabilities · Markdown version · Threadlinqs Intelligence