Skip to content
Noroxi
NVD / CVE Program· CNA qnap

CVE-2025-66281: A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions.

Noroxi assessment

Priority: Monitor (action score 27/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.45% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • According to the record, no fixed version is available yet.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions. The remote attackers 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 h5.3.4.3500 build 20260520 and later QuTS hero h6.0.0.3397 build 20260206 and later

MediumCVSS 6.9 · v4.0—No exploit No fix recorded
Published
Jun 10, 2026
Updated
Jul 23, 2026
EPSS
0.4% · 39th percentile

Report tools

JSON

Action score

27

Monitor

Low priority for now.

CVSS
27 / 40 · 6.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · qnap
6.9
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-66281

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for qnap records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
qnapqts
qnapquts hero

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • qnap qts5.2.0.2737 and later · before 5.2.9.3410
  • qnap quts heroh5.2.0.2737 and later · before h5.2.9.3410
  • qnap quts heroh5.3.0.3115 and later · before h5.3.4.3500
  • qnap quts heroh6.0.0.3324 and later · before h6.0.0.3397

Versions reported by the vendor

Affected version ranges reported by the assigning authority (qnap). Independent of NVD's CPE analysis and usually ahead of it.

  • QNAP Systems Inc. QTS

    • 5.2.0 and later · before 5.2.9.3410 build 20260214affected

  • QNAP Systems Inc. QuTS hero

    • h5.2.0 and later · before h5.2.9.3410 build 20260214affected
    • h5.3.0 and later · before h5.3.4.3500 build 20260520affected
    • ? and later · before h6.0.0.3397 build 20260206affected

Same product

qnap: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-2509Command Injection Vulnerability in QTS and QuTS heroKEV
    79This week
  • CVE-2018-19949If exploited, this command injection vulnerability could allow remote attackers to run arbitrary commands.KEV
    78This week
  • CVE-2019-7193This improper input validation vulnerability allows remote attackers to inject arbitrary code to the system.KEV
    73This week

Published before and after this one in the same product

  • ← EarlierCVE-2025-66279Jun 10, 2026 · A command injection vulnerability has been reported to affect several QNAP operating system versions.
    34Monitor
  • ← EarlierCVE-2025-66280Jun 10, 2026 · An integer overflow or wraparound vulnerability has been reported to affect several QNAP operating system versions.
    20Monitor
  • Later →CVE-2026-22893Jun 10, 2026 · A command injection vulnerability has been reported to affect several QNAP operating system versions.
    34Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-62848176 days apartA NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions.
    32Monitor
  • CVE-2025-29882285 days apartA NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions.
    21Monitor
  • CVE-2025-30267285 days apartA NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions.
    21Monitor
  • CVE-2025-30268285 days apartA NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions.
    21Monitor
  • CVE-2025-47205119 days apartA NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions.
    20Monitor
  • CVE-2025-52427250 days apartA NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions.
    20Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records