Vulnerabilities (CVE)

ESPHome is a system to control microcontrollers remotely through Home Automation systems. In versions 2025.9.0 through 2025.12.6, an integer overflow in the API component's protobuf decoder allows denial-of-service attacks when API encryption is not used. The bounds check `ptr + field_length > end` in `components/api/proto.cpp` can overflow when a malicious client sends a large `field_length` value. This affects all ESPHome device platforms (ESP32, ESP8266, RP2040, LibreTiny). The overflow bypas ... ESPHome is a system to control microcontrollers remotely through Home Automation systems. In versions 2025.9.0 through 2025.12.6, an integer overflow in the API component's protobuf decoder allows denial-of-service attacks when API encryption is not used. The bounds check `ptr + field_length > end` in `components/api/proto.cpp` can overflow when a malicious client sends a large `field_length` value. This affects all ESPHome device platforms (ESP32, ESP8266, RP2040, LibreTiny). The overflow bypasses the out-of-bounds check, causing the device to read invalid memory and crash. When using the plaintext API protocol, this attack can be performed without authentication. When noise encryption is enabled, knowledge of the encryption key is required. Users should upgrade to ESPHome 2025.12.7 or later to receive a patch, enable API encryption with a unique key per device, and follow the Security Best Practices.

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ESPHome is a system to control your ESP8266/ESP32 for Home Automation systems. Starting in version 2023.12.9 and prior to version 2024.2.2, editing the configuration file API in dashboard component of ESPHome version 2023.12.9 (command line installation and Home Assistant add-on) serves unsanitized data with `Content-Type: text/html; charset=UTF-8`, allowing a remote authenticated user to inject arbitrary web script and exfiltrate session cookies via Cross-Site scripting. It is possible for a ma ... ESPHome is a system to control your ESP8266/ESP32 for Home Automation systems. Starting in version 2023.12.9 and prior to version 2024.2.2, editing the configuration file API in dashboard component of ESPHome version 2023.12.9 (command line installation and Home Assistant add-on) serves unsanitized data with `Content-Type: text/html; charset=UTF-8`, allowing a remote authenticated user to inject arbitrary web script and exfiltrate session cookies via Cross-Site scripting. It is possible for a malicious authenticated user to inject arbitrary Javascript in configuration files using a POST request to the /edit endpoint, the configuration parameter allows to specify the file to write. To trigger the XSS vulnerability, the victim must visit the page` /edit?configuration=[xss file]`. Abusing this vulnerability a malicious actor could perform operations on the dashboard on the behalf of a logged user, access sensitive information, create, edit and delete configuration files and flash firmware on managed boards. In addition to this, cookies are not correctly secured, allowing the exfiltration of session cookie values. Version 2024.2.2 contains a patch for this issue.

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ESPHome is a system to control microcontrollers remotely through Home Automation systems. In version 2025.8.0 in the ESP-IDF platform, ESPHome's web_server authentication check can pass incorrectly when the client-supplied base64-encoded Authorization value is empty or is a substring of the correct value. This allows access to web_server functionality (including OTA, if enabled) without knowing any information about the correct username or password. This issue has been patched in version 2025.8. ... ESPHome is a system to control microcontrollers remotely through Home Automation systems. In version 2025.8.0 in the ESP-IDF platform, ESPHome's web_server authentication check can pass incorrectly when the client-supplied base64-encoded Authorization value is empty or is a substring of the correct value. This allows access to web_server functionality (including OTA, if enabled) without knowing any information about the correct username or password. This issue has been patched in version 2025.8.1.

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ESPHome is a system to control your ESP8266/ESP32. A security misconfiguration in the edit configuration file API in the dashboard component of ESPHome version 2023.12.9 (command line installation) allows authenticated remote attackers to read and write arbitrary files under the configuration directory rendering remote code execution possible. This vulnerability is patched in 2024.2.1.

ESPHome is a system to control the ESP8266/ESP32. Anyone with web_server enabled and HTTP basic auth configured on version 2021.9.1 or older is vulnerable to an issue in which `web_server` allows over-the-air (OTA) updates without checking user defined basic auth username & password. This issue is patched in version 2021.9.2. As a workaround, one may disable or remove `web_server`.