What’s Vulnerable › Vulnerabilities

CVE-2025-57808: ESP-IDF web_server basic auth bypass using empty or incomplete Authorization header

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2025-09-02 · updated 2026-10-19
• Weakness: CWE-303

Description

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.

Affected products

• Esphome Firmware: 2025.8.0

References

• https://github.com/esphome/esphome/commit/2aceb56606ec8afec5f49c92e140c8050a6ccbe5
• https://github.com/esphome/esphome/security/advisories/GHSA-mxh2-ccgj-8635
• https://github.com/esphome/esphome/security/advisories/GHSA-mxh2-ccgj-8635

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