CVE-2026-7548Public exploitNetwork attack vector

Authenticated command execution via unescaped USSD input

Published May 1, 2026 · Updated May 1, 2026

OS command injection in TOTOLINK NR1800X Firmware 9.1.0u.6279_B20210910 allows remote authenticated users to execute shell commands. The sub_41A68C setUssd path in /cgi-bin/cstecgi.cgi inserts the attacker-controlled ussd value into an AT+CUSD command string and passes it to system without neutralizing shell metacharacters. A valid management session is required, and successful injection runs commands with the web service process privileges on the router.

CVSS severity8.7
High
EPSS probability1.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in TOTOLINK NR1800X Firmware 9.1.0u.6279_B20210910 allows remote authenticated users to execute shell commands. The sub_41A68C setUssd path in /cgi-bin/cstecgi.cgi inserts the attacker-controlled ussd value into an AT+CUSD command string and passes it to system without neutralizing shell metacharacters. A valid management session is required, and successful injection runs commands with the web service process privileges on the router.

The record

CVE
CVE-2026-7548
Published
May 1, 2026
Updated
May 1, 2026
Vendor
TOTOLINK
Product
NR1800X Firmware
Classifications
CWE-77, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=9.1.0u.6279_B20210910

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TOTOLINK · NR1800X Firmwareversion=9.1.0u.6279_B20210910

Published CVSS scores

8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.7VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1059.004Unix Shell

Public exploit references

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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