CVE-2026-9404: A vulnerability was identified in Totolink A8000RU 7.1cu.643_b20200521

This week

CRITICAL 9.8REMOTE

CVE-2026-9404 is a critical-severity flaw (CVSS 9.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
CISA SSVC: public proof of concept
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 22%)
CISA exploited list	No
Weakness	CWE-77, CWE-78
Published	2026-05-24
Last modified	2026-07-23

Publisher (CNA): VulDB

Last updated 2026-07-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-05-24 23:16 UTCPublished CVE record published
2026-07-23 11:10 UTCUpdated Record last modified

Exact fixes by distribution

Fedora ELN · clash-meta · FIXED · 1.19.33-1.eln159 · FEDORA-2026-7dfb64c5e1 · source

sudo dnf upgrade --advisory=FEDORA-2026-7dfb64c5e1

Fedora 46 · vulkan-utility-libraries · FIXED · 1.4.363.0-1.fc46 · FEDORA-2026-994176daf5 · source

sudo dnf upgrade --advisory=FEDORA-2026-994176daf5

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/Litengzheng/vuldb_new2/blob/main/A8000RU/vul_336/README.md

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-9404?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-9404 being exploited?

CVE-2026-9404 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-9404 affect?

CVE-2026-9404 affects affected software. Severity is critical (CVSS 9.8). 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

How urgent is CVE-2026-9404?

Priority 65/100. Critical severity; CISA SSVC: public proof of concept; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

References

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