CVE-2025-57808Public exploit

Authentication bypass via prefix-length credential comparison

Published Sep 2, 2025 · Updated Sep 2, 2025

Authentication bypass in ESPHome 2025.8.0 on ESP-IDF allows remote attackers to access web_server functions over the local network. AsyncWebServerRequest::authenticate compares only the client value's length against the Base64-encoded user:password digest, so an empty value or matching prefix passes. No credentials or user interaction are required; exposed functions include protected content and OTA firmware updates when OTA is enabled.

CVSS severity8.1
High
EPSS probability1.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in ESPHome 2025.8.0 on ESP-IDF allows remote attackers to access web_server functions over the local network. AsyncWebServerRequest::authenticate compares only the client value's length against the Base64-encoded user:password digest, so an empty value or matching prefix passes. No credentials or user interaction are required; exposed functions include protected content and OTA firmware updates when OTA is enabled.

The record

CVE
CVE-2025-57808
Published
Sep 2, 2025
Updated
Sep 2, 2025
Vendor
ESPHome
Product
ESPHome
Classifications
CWE-303, T1190
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion== 2025.8.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

ESPHome · ESPHomeversion== 2025.8.0

Published CVSS scores

8.1GitHub, Inc.CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-303Incorrect Implementation of Authentication Algorithm
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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