CVE-2026-23833 is a low severity vulnerability with a CVSS score of 0.0. No known exploits currently, and patches are available.
Very low probability of exploitation
EPSS predicts the probability of exploitation in the next 30 days based on real-world threat data, complementing CVSS severity scores with actual risk assessment.
An integer overflow in the API component's protobuf decoder allows denial-of-service attacks when API encryption is not used.
The bounds check ptr + field_length > end in components/api/proto.cpp can overflow when a malicious client sends a large field_length value. This affects all ESPHome device platforms (ESP32, ESP8266, RP2040, LibreTiny). The overflow bypasses the out-of-bounds check, causing the device to read invalid memory and crash.
When using the plaintext API protocol, this attack can be performed without authentication. When noise encryption is enabled, knowledge of the encryption key is required.
ESPHome 2025.9.0 through 2025.12.6
Low - Users following Security Best Practices with API encryption enabled are not affected without knowledge of the encryption key.
Denial-of-service. An attacker with network access to port 6053 can crash and reboot the device.
Thanks to @Mat931 for responsibly reporting this vulnerability.
Please cite this page when referencing data from Strobes VI. Proper attribution helps support our vulnerability intelligence research.