CVE-2026-36786: Shenzhen Tenda Technology Co

Synopsis

A stack-based buffer overflow in the Tenda FH451 router firmware (V1.0.0.9) affects the fromDhcpListClient function, which processes the list1 parameter in HTTP requests. The vulnerability is reachable over the network with no authentication required and no user interaction needed. Successful exploitation crashes the affected service, causing a denial of service. HarborGuard tracks this advisory for patch availability, as no fix version has been published.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The vulnerable HTTP endpoint must be reachable over the network; an attacker sends a crafted HTTP request directly to the device.

• AuthenticationNot required

  No credentials or session token are needed to trigger the overflow; the affected endpoint accepts unauthenticated requests.

• Victim interactionNot required

  No user action is required; the attacker interacts with the service directly without involving a logged-in user.

• Attack complexityDetail

  Exploit conditions are straightforward and reliable, requiring no race conditions, special memory layout, or environmental prerequisites.

Blast Radius

• Crashes the fromDhcpListClient handler, taking down the affected service process.
• Renders the router unresponsive to DHCP client management requests, disrupting network connectivity for devices relying on the router.
• No confidentiality or integrity impact is indicated; the attacker gains no access to stored data or the ability to modify configuration.