Is there a public PoC exploit available for EUVD-2026-31546?

Yes, a public proof-of-concept exploit is available for EUVD-2026-31546. Prioritise patching immediately. EPSS: 0.9%.

Totolink A8000RU EUVD-2026-31546

Q: What is the CVSS score of EUVD-2026-31546?

EUVD-2026-31546 has a CVSS 4.0 base score of 8.9 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.9%.

| CVE-2026-9386 HIGH

OS Command Injection (CWE-78)

2026-05-24 VulDB

GHSA-p623-gg4q-6fv7

Command Injection A8000Ru

8.9

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

8.9 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

CVE Published

Jun 22, 2026 - 06:03 cve.org

HIGH 8.9

Analysis Generated

Jun 08, 2026 - 09:39 vuln.today

Severity Changed

May 26, 2026 - 19:07 NVD

CRITICAL HIGH

CVSS changed

May 26, 2026 - 19:07 NVD

9.8 (CRITICAL) 8.9 (HIGH)

DescriptionCVE.org

A vulnerability was identified in Totolink A8000RU 7.1cu.643_b20200521. Impacted is the function setLanguageCfg of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. Such manipulation of the argument lang leads to os command injection. The attack may be performed from remote. The exploit is publicly available and might be used.

AnalysisAI

OS command injection in the Totolink A8000RU router (firmware 7.1cu.643_b20200521) allows remote unauthenticated attackers to execute arbitrary operating system commands through the setLanguageCfg function in /cgi-bin/cstecgi.cgi. The flaw is triggered by manipulating the lang argument in the Web Management Interface, with publicly available exploit code existing and SSVC classifying the issue as automatable with total technical impact. EPSS sits at 0.89% (76th percentile), indicating moderate but non-trivial exploitation probability.

Technical ContextAI

The affected component is the cstecgi.cgi binary, a common CGI handler in Totolink router firmware that dispatches Web Management Interface requests to internal handler functions such as setLanguageCfg. The root cause is CWE-78 (Improper Neutralization of Special Elements used in an OS Command), meaning the lang parameter value is concatenated into a shell command without proper sanitization or use of safe execution primitives. Per the CPE (cpe:2.3:a:totolink:a8000ru), the vulnerability lives in the embedded firmware web stack of the A8000RU gigabit router, where CGI handlers typically run with root privileges, giving any successful command injection full system control.

RemediationAI

No vendor-released patch identified at time of analysis - the references point only to VulDB tracking entries, a public exploit write-up at https://github.com/Litengzheng/vuldb_new2/blob/main/A8000RU/vul_333/README.md, and the Totolink vendor site (https://www.totolink.net/) without a specific firmware fix advisory, so administrators should check Totolink's support portal for an updated firmware build superseding 7.1cu.643_b20200521. As compensating controls, disable remote (WAN-side) web management on the A8000RU so /cgi-bin/cstecgi.cgi is not reachable from the internet (trade-off: loss of remote admin convenience), restrict LAN-side access to the admin interface using ACLs or VLAN segmentation to trusted management hosts only (trade-off: added operational complexity for legitimate admins), and place the device behind a reverse proxy or firewall that blocks requests containing shell metacharacters in the lang parameter of cstecgi.cgi (trade-off: may break legitimate language switching). Consider replacing the device if no firmware update is forthcoming.