CVE-2026-4253: Tenda AC8 Web UploadCfg route_set_user_policy_rule os command injection

Vulnerability summary

CVE-2026-4253 is a high (CVSS 7.2) Command Injection vulnerability in tenda ac8_firmware. EPSS estimates a 8.56% chance of exploitation in the next 30 days, higher than 95% of scored vulnerabilities. 2 public exploits are recorded.

Timeline

1. 16-03-2026
   PublishedVulnerability first disclosed.
2. 16-03-2026
   Last modifiedVulnerability information updated.

Description

A security flaw has been discovered in Tenda AC8 16.03.50.11. This affects the function route_set_user_policy_rule of the file /cgi-bin/UploadCfg of the component Web Interface. The manipulation of the argument wans.policy.list1 results in os command injection. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks.

• CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')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.
• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.