RCE in Totolink A8000ru

CVE-2026-9404

A vulnerability was identified in Totolink A8000RU 7.1cu.643_b20200521. This affects the function setDdnsCfg of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. Such manipulation of the argument provider leads to os command injection. The attack may be launched remotely. The exploit is publicly available and might be used.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.033 (87.9th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 87.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-9404: rose from 0.017 to 0.033.

EPSS over last 30 days · oldest: 0.017 · newest: 0.033 · change: +0.015

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-9404?
CVE-2026-9404 is a critical-severity vulnerability in Totolink A8000ru, classified under Command Injection. CVSS score: 9.8/10. Published 2026-05-24.
How severe is CVE-2026-9404?
Critical severity. CVSS v3 base score is 9.8 out of 10.