Tenda AC18 15.03.05.05_multi /goform/SetSambaCfg guestuser command injection

Summaryinfo

A vulnerability marked as critical has been reported in Tenda AC18 15.03.05.05_multi. This affects an unknown part of the file /goform/SetSambaCfg. The manipulation of the argument guestuser leads to command injection. This vulnerability is uniquely identified as CVE-2026-31255. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Tenda AC18 15.03.05.05_multi. This issue affects an unknown code of the file /goform/SetSambaCfg. The manipulation of the argument guestuser with an unknown input leads to a command injection vulnerability. Using CWE to declare the problem leads to CWE-77. The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A command injection vulnerability exists in Tenda AC18 V15.03.05.05_multi. The vulnerability is located in the /goform/SetSambaCfg interface, where improper handling of the guestuser parameter allows attackers to execute arbitrary system commands.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-31255 since 03/09/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/27/2026). The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Tenda

Name

• AC18

Version

• 15.03.05.05_multi

License

• commercial

Website

• Vendor: https://www.tenda.com.cn/

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