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`).
Advisories
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Fixes
Solution
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Workaround
No workaround given by the vendor.
References
History
Wed, 05 Aug 2026 16:30:00 +0000
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ssvc
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Wed, 05 Aug 2026 15:00:00 +0000
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Esphome
Esphome esphome |
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Esphome
Esphome esphome |
Wed, 05 Aug 2026 13:15:00 +0000
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| Description | 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`). | |
| Title | ESPHome external_components file:// Scheme Validation Bypass Leading to Remote Code Execution | |
| Weaknesses | CWE-184 | |
| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: TuranSec
Published:
Updated: 2026-08-05T15:29:29.949Z
Reserved: 2026-08-05T12:23:34.966Z
Link: CVE-2026-71259
Updated: 2026-08-05T15:29:27.291Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-08-05T15:30:17Z
Weaknesses