CVE-2026-71259: ESPHome external_components file:// Scheme Validation Bypass Leading to Remote Code Execution

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-05 · updated 2026-08-26
Weakness: CWE-184

Description

ESPHome through 2026.7.0-dev contains an operator-precedence bug in the cv.url validator in esphome/config_validation.py. Because binds tighter than , any file: URI passes validation regardless of netloc. This validator gates the field of the external_components YAML directive's git source schema, which is passed to (git supports file:// natively).

Affected products

esphome: through 2026.7.0

References

https://github.com/esphome/esphome
https://github.com/esphome/esphome/blob/dev/esphome/config_validation.py

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