CVE-2026-23892

OctoPrint provides a web interface for controlling consumer 3D printers. OctoPrint versions up to and including 1.11.5 are affected by a (theoretical) timing attack vulnerability that allows API key extraction over the network. Due to using character based comparison that short-circuits on the first mismatched character during API key validation, rather than a cryptographical method with static runtime regardless of the point of mismatch, an attacker with network based access to an affected OctoPrint could extract API keys valid on the instance by measuring the response times of the denied access responses and guess an API key character by character. The vulnerability is patched in version 1.11.6. The likelihood of this attack actually working is highly dependent on the network's latency, noise and similar parameters. An actual proof of concept was not achieved so far. Still, as always administrators are advised to not expose their OctoPrint instance on hostile networks, especially not on the public Internet.

OctoPrint provides a web interface for controlling consumer 3D printers. OctoPrint versions up to and including 1.11.5 are affected by a (theoretical) timing attack vulnerability that allows API key extraction over the network. Due to using character based comparison that short-circuits on the first mismatched character during API key validation, rather than a cryptographical method with static runtime regardless of the point of mismatch, an attacker with network based access to an affected OctoPrint could extract API keys valid on the instance by measuring the response times of the denied access responses and guess an API key character by character. The vulnerability is patched in version 1.11.6. The likelihood of this attack actually working is highly dependent on the network's latency, noise and similar parameters. An actual proof of concept was not achieved so far. Still, as always administrators are advised to not expose their OctoPrint instance on hostile networks, especially not on the public Internet.

### Impact OctoPrint versions up to and including 1.11.5 are affected by a (theoretical) timing attack vulnerability that allows API key extraction over the network. Due to using character based comparison that short-circuits on the first mismatched character during API key validation, rather than a cryptographical method with static runtime regardless of the point of mismatch, an attacker with network based access to an affected OctoPrint could extract API keys valid on the instance by measuring the response times of the denied access responses and guess an API key character by character. ### Patches The vulnerability will be patched in version 1.11.6. ### Workaround The likelihood of this attack actually working is highly dependent on the network's latency, noise and similar parameters. An actual proof of concept was not achieved so far. Still, as always administrators are advised to not expose their OctoPrint instance on hostile networks, especially not on the public Internet! ### Credits This vulnerability was discovered and responsibly disclosed to OctoPrint by [Knox Liu](https://github.com/yueyueL).

### Impact OctoPrint versions up to and including 1.11.5 are affected by a (theoretical) timing attack vulnerability that allows API key extraction over the network. Due to using character based comparison that short-circuits on the first mismatched character during API key validation, rather than a cryptographical method with static runtime regardless of the point of mismatch, an attacker with network based access to an affected OctoPrint could extract API keys valid on the instance by measuring the response times of the denied access responses and guess an API key character by character. ### Patches The vulnerability will be patched in version 1.11.6. ### Workaround The likelihood of this attack actually working is highly dependent on the network's latency, noise and similar parameters. An actual proof of concept was not achieved so far. Still, as always administrators are advised to not expose their OctoPrint instance on hostile networks, especially not on the public Internet! ### Credits This vulnerability was discovered and responsibly disclosed to OctoPrint by [Knox Liu](https://github.com/yueyueL).

OctoPrint proporciona una interfaz web para controlar impresoras 3D de consumo. Las versiones de OctoPrint hasta la 1.11.5 inclusive están afectadas por una vulnerabilidad (teórica) de ataque de temporización que permite la extracción de claves API a través de la red. Debido al uso de una comparación basada en caracteres que se interrumpe en el primer carácter no coincidente durante la validación de la clave API, en lugar de un método criptográfico con tiempo de ejecución estático independientemente del punto de no coincidencia, un atacante con acceso basado en red a una instancia de OctoPrint afectada podría extraer claves API válidas en la instancia midiendo los tiempos de respuesta de las respuestas de acceso denegado y adivinar una clave API carácter por carácter. La vulnerabilidad está parcheada en la versión 1.11.6. La probabilidad de que este ataque funcione realmente depende en gran medida de la latencia, el ruido y parámetros similares de la red. Una prueba de concepto real no se ha logrado hasta ahora. Aun así, como siempre, se aconseja a los administradores que no expongan su instancia de OctoPrint en redes hostiles, especialmente no en la Internet pública.