CVE-2026-51269

schreibfaul1 ESP32-audioI2S 3.4.5 has a heap-based buffer overflow vulnerability in the connecttospeech() function. The application accepts attacker-controlled long speech text input, performs URL encoding, and directly appends the encoded result into a fixed ps_ptr heap buffer when constructing HTTP TTS request headers. Lack of input length validation and boundary checking allows remote attackers to craft oversized input to trigger out-of-bounds heap write, resulting in arbitrary code execution.