CVE-2026-36576: An OS command injection vulnerability in the app

Synopsis

An OS command injection vulnerability in the app.py component of openlabs docker-wkhtmltopdf-aas (up to commit 9f50579) allows an unauthenticated attacker to inject and execute arbitrary operating system commands by sending a crafted HTTP POST request. No authentication or victim interaction is required, and the service is reachable directly over the network. Successful exploitation gives the attacker full control over the host process, including the ability to read, modify, or destroy data and crash the service. HarborGuard is tracking this advisory and will make a patched-image rebuild available the moment an upstream fix is published.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The vulnerable app.py endpoint is exposed over the network, so an attacker must be able to send an HTTP POST request to the service from a remote host.

• AuthenticationNot required

  No credentials or session token are needed; the injection point is reachable by any unauthenticated caller.

• Victim interactionNot required

  Exploitation is fully server-side and requires no action from any user or administrator.

• Attack complexityDetail

  Attack complexity is low, meaning the exploit is reliable and reproducible without depending on race conditions, specific memory layouts, or other variable environmental factors.

Blast Radius

• A successful attacker executes arbitrary OS commands in the context of the container process, gaining the same filesystem and network access the process holds.
• All data accessible to the running process, including converted documents, temporary files, and any mounted secrets or credentials, can be read or exfiltrated.
• The attacker can write or delete files on the container filesystem, modifying application behavior or destroying stored content.
• The container process can be crashed or made to consume all available resources, taking the wkhtmltopdf conversion service offline.