Vulnerability-Lookup

CVE-2026-71259 (GCVE-0-2026-71259)

Vulnerability from cvelistv5 – Published: 2026-08-05 12:26 – Updated: 2026-08-05 15:29

Title

ESPHome external_components file:// Scheme Validation Bypass Leading to Remote Code Execution

Summary

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`).

Severity

8.6 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-184

Assigner

TuranSec

References

2 references

URL	Tags
https://github.com/esphome/esphome
https://github.com/esphome/esphome/blob/dev/espho…

Impacted products

1 product

Vendor	Product	Version
esphome	esphome	Affected: 0 , ≤ 2026.7.0 (semver)

Credits

Alibek Baxtiyorov

Show details on NVD website

JSON

To clipboard

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GHSA-2G7J-RV69-9W67

Vulnerability from github – Published: 2026-08-05 15:32 – Updated: 2026-08-05 15:32

Details

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).

Severity

8.6 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-71259"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-184"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-05T13:24:49Z",
    "severity": "HIGH"
  },
  "details": "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\u0027s 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\u0027s import machinery via ESPHome\u0027s component loader, executing arbitrary Python code when the YAML configuration is processed (e.g. via `esphome config`/`esphome run`).",
  "id": "GHSA-2g7j-rv69-9w67",
  "modified": "2026-08-05T15:32:19Z",
  "published": "2026-08-05T15:32:19Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-71259"
    },
    {
      "type": "WEB",
      "url": "https://github.com/esphome/esphome"
    },
    {
      "type": "WEB",
      "url": "https://github.com/esphome/esphome/blob/dev/esphome/config_validation.py"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-71259 (GCVE-0-2026-71259)

GHSA-2G7J-RV69-9W67

Tags

Sightings

Nomenclature