ESPHome up to 2026.7.0 URL Validator config_validation.py cv.url input validation

Summaryinfo

A vulnerability classified as problematic was found in ESPHome up to 2026.7.0. This affects the function cv.url of the file esphome/config_validation.py of the component URL Validator. The manipulation results in input validation. This vulnerability is known as CVE-2026-71259. Attacking locally is a requirement. No exploit is available.

Detailsinfo

A vulnerability classified as problematic has been found in ESPHome up to 2026.7.0. Affected is the function cv.url of the file esphome/config_validation.py of the component URL Validator. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

ESPHome through 2026.7.0-dev contains an operator-precedence bug in the cv.url() validator in esphome/config_validation.py: `if parsed.scheme and parsed.netloc or parsed.scheme == "file": return parsed.geturl()`. Because `and` binds tighter than `or`, any file: URI passes validation regardless of netloc. This validator gates the `url:` field of the external_components YAML directive's git source schema, which is passed to `git clone` (git supports file:// natively). A crafted `external_components` block with `url: "file:///attacker/repo"` clones an attacker-controlled local path, which is then added to Python's import machinery via ESPHome's component loader, executing arbitrary Python code when the YAML configuration is processed (e.g. via `esphome config`/`esphome run`).

The advisory is available at github.com. This vulnerability is traded as CVE-2026-71259 since 08/05/2026. The exploitability is told to be easy. Local access is required to approach this attack. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Name

• ESPHome

Version

• 2026.0
• 2026.1
• 2026.2
• 2026.3
• 2026.4
• 2026.5
• 2026.6
• 2026.7.0

CPE 2.3info

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CPE 2.2info

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