CVE-2026-71259
HIGHCVE-2026-71259 is a high-severity (CVSS 8.6) CWE-184 vulnerability. O3 Security confirms whether CVE-2026-71259 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
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":…
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).
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-71259 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-71259 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-71259. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-71259 in your dependencies?
O3 detects CVE-2026-71259 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.