CVE-2026-71260: ESPHome web_server Plaintext Password Disclosure via JSON "value" Field

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-05 · updated 2026-08-26
Weakness: CWE-522

Description

ESPHome through 2026.7.0-dev discloses plaintext passwords via its web_server component. In WebServer::text_json_ (esphome/components/web_server/web_server.cpp), a text entity configured with mode: password (TEXT_MODE_PASSWORD) has its JSON "state" field correctly masked as "********", but the same serialization path unconditionally writes the raw password into the JSON "value" field via set_json_icon_state_value/set_json_value.

Affected products

esphome: through 2026.7.0

References

https://github.com/esphome/esphome
https://github.com/esphome/esphome/blob/dev/esphome/components/web_server/web_server.cpp

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