CVE-2026-1791Network attack vector

Web shell upload via unfiltered file handling

Published Feb 4, 2026 · Updated Feb 4, 2026

Unrestricted file upload in Hillstone Networks Operation Security Gateway V5.5ST00001B113 allows remote authenticated users to place a web shell. The file-upload path lacks effective validation and filtering of user-supplied files, so it accepts arbitrary malicious file types. Administrator privileges are required; the published assessment limits the direct consequence to a service interrupt and does not report data access or modification.

CVSS severity2.7
Low
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in Hillstone Networks Operation Security Gateway V5.5ST00001B113 allows remote authenticated users to place a web shell. The file-upload path lacks effective validation and filtering of user-supplied files, so it accepts arbitrary malicious file types. Administrator privileges are required; the published assessment limits the direct consequence to a service interrupt and does not report data access or modification.

The record

CVE
CVE-2026-1791
Published
Feb 4, 2026
Updated
Feb 4, 2026
Vendor
Hillstone Networks
Product
Operation Security Gateway
Classifications
CWE-434, CAPEC-650, T1505.003
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Feb 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=V5.5ST00001B113

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Hillstone Networks · Operation Security Gatewayversion=V5.5ST00001B113

Published CVSS scores

2.7Hillstone NetworksCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L

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.

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
CAPEC-650Upload a Web Shell to a Web Server
T1505.003Server Software Component: Web Shell

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

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Your stack

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