CVE-2026-51268 in ESP32-audioI2S
Summary
by MITRE • 07/28/2026
schreibfaul1 ESP32-audioI2S 3.4.5 has a heap-based buffer overflow vulnerability in the host parsing logic. The dismantle_host() function parses untrusted host and URL input, and subsequent code uses clone_from() to copy parsed host, request host, extension and query_string segments into fixed heap buffers without boundary checking.
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Analysis
by VulDB Data Team • 07/28/2026
The schreibfaul1 ESP32-audioI2S library version 3.4.5 contains a critical heap-based buffer overflow vulnerability that stems from inadequate input validation in the host parsing logic. This vulnerability resides within the dismantle_host() function which processes untrusted host and URL input parameters without proper boundary checking mechanisms. The flaw represents a classic example of improper input validation that allows attackers to manipulate memory structures through crafted malicious inputs.
The technical implementation of this vulnerability involves the function's handling of parsed host components including host segments, request hosts, extensions, and query strings. When these elements are processed, the code employs clone_from() operations to copy data into fixed-size heap buffers without verifying that the source data length exceeds the destination buffer capacity. This fundamental lack of bounds checking creates an exploitable condition where maliciously crafted URL inputs can cause data to overflow into adjacent memory regions, potentially leading to arbitrary code execution or system instability.
From an operational impact perspective, this vulnerability affects systems utilizing the ESP32-audioI2S library for audio streaming applications that rely on HTTP host parsing functionality. Attackers could exploit this weakness by providing specially crafted URLs containing overly long hostnames or path components that exceed the fixed buffer sizes allocated for storage. The vulnerability is particularly concerning in IoT and embedded audio streaming environments where these devices may be exposed to untrusted network inputs. The heap overflow condition could result in application crashes, memory corruption, or potentially allow remote code execution depending on memory layout and exploitation circumstances.
This vulnerability aligns with CWE-121 Heap-based Buffer Overflow which specifically addresses buffer overflows occurring in heap memory regions due to insufficient boundary checks during memory copying operations. The ATT&CK framework categorizes this as a software vulnerability that could enable privilege escalation or arbitrary code execution through remote exploitation. The attack surface is particularly relevant for IoT devices and embedded systems running on ESP32 microcontrollers where audio streaming applications are prevalent. Organizations should prioritize patching this vulnerability as it represents a significant risk to system integrity and security in environments where untrusted input handling is required.
The remediation approach requires implementing proper bounds checking mechanisms before any memory copying operations occur, ensuring that source data lengths are validated against destination buffer capacities. Additionally, the code should employ safer string handling functions that automatically perform bounds checking or utilize memory-safe programming practices to prevent similar vulnerabilities from occurring in future implementations.