5.1

CVE-2025-66274: qnap systems inc. qts NULL Pointer Dereference

CVSS: 5.1v4.0MediumModified
Published 11-02-2026Last modified 09-06-2026
Open JSON

Vulnerability summary

CVE-2025-66274 is a medium (CVSS 5.1) NULL Pointer Dereference vulnerability in qnap systems inc. qts. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.5% of scored vulnerabilities.

Overall risk
20/100
0100
Low · default modelHow is this calculated?
CVSS score
5.1/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.43%
0%100%
Low · +0.05 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 11-02-2026
    PublishedVulnerability first disclosed.
  2. 09-06-2026
    Last modifiedVulnerability information updated.

Description

A NULL pointer dereference 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 launch a denial-of-service (DoS) attack. 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 h5.3.2.3354 build 20251225 and later QuTS hero h6.0.0.3397 build 20260206 and later

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.43%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

+0.05 pp

From 0.38% on 22-09-2026

22-09-202622-10-2026
EPSS score
0.43%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Qnap systems inc.2 products
  • qts≥ 5.2.0, < 5.2.9.3410 build 20260214
  • quts hero≥ h5.2.0, < h5.2.9.3410 build 20260214 | ≥ h5.3.0, < h5.3.2.3354 build 20251225 | ≥ ?, < h6.0.0.3397 build 20260206
Qnap1 product
  • quts_heroh5.3.0.3115:build_20250430 | h5.3.0.3145:build_20250530 | h5.3.0.3192:build_20250716 | h5.3.1.3250:build_20250912 | h5.3.1.3292:build_20251024

2 vendors · 3 products

References

1 links