CVE-2026-19852Network attack vector

Stored script execution via unrestricted file upload

Published Aug 24, 2026 · Updated Aug 24, 2026

Arbitrary file upload in CyberTutor NewSiteServer (NSS) allows remote attackers to store malicious HTML through unauthenticated requests. TWCERT/CC has not disclosed the upload endpoint or the validation error that permits dangerous file types to be accepted. The uploaded HTML must be opened by a user, enabling script execution in the site's origin with limited confidentiality and integrity impact.

CVSS severity5.1
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Arbitrary file upload in CyberTutor NewSiteServer (NSS) allows remote attackers to store malicious HTML through unauthenticated requests. TWCERT/CC has not disclosed the upload endpoint or the validation error that permits dangerous file types to be accepted. The uploaded HTML must be opened by a user, enabling script execution in the site's origin with limited confidentiality and integrity impact.

The record

CVE
CVE-2026-19852
Published
Aug 24, 2026
Updated
Aug 24, 2026
Vendor
Zhejiang Zoneland Zongheng Network Technology Co., Ltd.
Product
NewSiteServer (NSS)
Classifications
CWE-434, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=all

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zhejiang Zoneland Zongheng Network Technology Co., Ltd. · NewSiteServer (NSS)version=all

Published CVSS scores

6.1TWCERT/CCCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.1TWCERT/CCCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1189Drive-by Compromise

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo