ESPHome external_components file:// Scheme Validation Bypass Leading to Remote Code Execution (CVE-2026-71259) | HOL Guard CVE

High · CVSS 8.6CVE-2026-71259

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

Answer in brief

CVE-2026-71259 records a High severity (CVSS 8.6) vulnerability in ESPHome external_components file:// Scheme Validation Bypass Leading to Remote Code Execution. The current sources do not mark it as known exploited. The current feed maps esphome/esphome (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 5, 2026Updated Aug 26, 2026Source checked Sep 21, 2026First seen by HOL Aug 5, 2026Material review Aug 26, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.6
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 8.6. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps esphome/esphome (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
esphome/esphomegeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for esphome/esphome.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 26, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source 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).

Quoted source text, attributed separately from HOL analysis.