CVE-2026-6140 Totolink CVE debrief

Who should care

Defenders responsible for Totolink A7100RU devices, particularly those exposed to remote access, should assess their exposure and prioritize patching or mitigating this vulnerability.

Why it matters

CVE-2026-6140 is a high-severity OS command injection vulnerability in Totolink A7100RU devices. Defenders should prioritize patching or mitigating this vulnerability to prevent potential remote exploitation and arbitrary code execution.

• Remote attackers may exploit this vulnerability to inject OS commands
• Successful exploitation could lead to arbitrary code execution
• Defenders should verify and apply patches to prevent exploitation
• Exposure requires verification from official sources

Technical summary

The vulnerability is caused by a weakness in the UploadFirmwareFile function of the /cgi-bin/cstecgi.cgi file in the CGI Handler component of Totolink A7100RU 7.4cu.2313_b20191024. An attacker can inject OS commands by manipulating the FileName argument. The CVSS score for this vulnerability is 8.9, indicating a high severity. Defenders should prioritize verifying and applying patches for the affected Totolink A7100RU device, particularly those exposed to remote access. The vulnerability allows remote attackers to inject OS commands, which could lead to arbitrary code execution.

Defensive priority

Defenders should prioritize verifying and applying patches for the affected Totolink A7100RU device, particularly those exposed to remote access.

Recommended defensive actions

• Verify and apply patches for Totolink A7100RU 7.4cu.2313_b20191024
• Restrict access to the /cgi-bin/cstecgi.cgi endpoint
• Monitor for suspicious activity on affected devices
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and affected product. Additional information is available from Vuldb. The vulnerability has a high CVSS score of 8.9, indicating a high severity. The affected product is Totolink A7100RU 7.4cu.2313_b20191024. Defenders should verify and apply patches to prevent exploitation.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.