CVE-2026-45087: Dalfox: Unauthenticated Remote Code Execution via `found-action` in Dalfox Server Mode

Synopsis

An unauthenticated remote code execution vulnerability exists in Dalfox, the open-source XSS scanning tool, when it is run in REST API server mode. The server binds to all interfaces by default with no authentication required, and attacker-supplied JSON in a POST /scan request can set arbitrary shell commands via the FoundAction and FoundActionShell fields, which are passed directly into scan execution without sanitization. Successful exploitation gives the attacker full command execution on the host running the Dalfox server process. No fix version has been published yet; HarborGuard tracks this advisory and will make a patched-image rebuild available as soon as an upstream fix is released.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker must reach the Dalfox server port (default 6664) over the network, as the service binds to 0.0.0.0 and is exposed to any host that can route to it.

• AuthenticationNot required

  No API key or credentials are required by default; the server accepts unauthenticated POST requests unless the operator has explicitly passed the --api-key flag at startup.

• Victim interactionNot required

  Exploitation is fully automated and requires no action from any user or operator on the target system.

• Attack complexityDetail

  The exploit is reliable and condition-free; the attacker simply sends a crafted JSON body to a known endpoint with no race conditions or environmental dependencies to satisfy.

Blast Radius

• The attacker executes arbitrary shell commands as the OS user running the Dalfox server process, gaining full control over that process and its accessible filesystem paths.
• All secrets, credentials, and environment variables visible to the Dalfox process (such as API tokens or cloud credentials injected at container runtime) are readable.
• The attacker can modify or delete files accessible to the process, including scan result data and any mounted volumes.
• The Dalfox service itself can be crashed or hijacked, disrupting any automated scanning pipelines that depend on it.