CVE-2026-9455Public exploitNetwork attack vector

Unauthenticated command execution via FileName interpolation

Published May 25, 2026 · Updated May 25, 2026

OS command injection in TOTOLINK A8000RU 7.1cu.643_b20200521 allows remote attackers to execute arbitrary commands via FileName. UploadOpenVpnCert in /cgi-bin/cstecgi.cgi formats the untrusted value into a command buffer and passes it through CsteSystem to execv without neutralizing command syntax. No credentials or user interaction are required; commands run in the router operating-system context and can read or alter router data or interrupt services.

CVSS severity9.8
Critical
EPSS probability1.91%
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 A8000RU 7.1cu.643_b20200521 allows remote attackers to execute arbitrary commands via FileName. UploadOpenVpnCert in /cgi-bin/cstecgi.cgi formats the untrusted value into a command buffer and passes it through CsteSystem to execv without neutralizing command syntax. No credentials or user interaction are required; commands run in the router operating-system context and can read or alter router data or interrupt services.

The record

CVE
CVE-2026-9455
Published
May 25, 2026
Updated
May 25, 2026
Vendor
TOTOLINK
Product
A8000RU
Classifications
CWE-78, CWE-77, T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 25, 2026CVE publishedPublication date reported by the CVE source.
  2. May 25, 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=7.1cu.643_b20200521

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

TOTOLINK · A8000RUversion=7.1cu.643_b20200521

Published CVSS scores

10.0VulDBAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
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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