CVE-2026-71259
ESPHome external_components file:// Scheme Validation Bypass Leading to Remote Code Execution
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`).
INFO
Published Date :
Aug. 5, 2026, 1:24 p.m.
Last Modified :
Aug. 5, 2026, 1:24 p.m.
Remotely Exploit :
No
Source :
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Affected Products
The following products are affected by CVE-2026-71259
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c |
Solution
- Update ESPHome to a version later than 2026.7.0-dev.
- Review and sanitize external component URLs.
- Avoid cloning local file paths as components.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-71259.
| URL | Resource |
|---|---|
| https://github.com/esphome/esphome | |
| https://github.com/esphome/esphome/blob/dev/esphome/config_validation.py |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-71259 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-71259
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-71259 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-71259 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 05, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'esphome', 'product': 'esphome', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2026.7.0'}], 'programFiles': ['esphome/config_validation.py', 'esphome/components/external_components/__init__.py'], 'defaultStatus': 'unaffected'}] Added 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`). Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H Added CWE CWE-184 Added Reference https://github.com/esphome/esphome Added Reference https://github.com/esphome/esphome/blob/dev/esphome/config_validation.py