Facebook mvfst Heap-Buffer-Overflow Vulnerability in QUIC Session

A heap-buffer-overflow vulnerability has been identified in Facebook's mvfst library, specifically in versions from v2025.03.24.00 prior to v2025.07.07.00. The vulnerability can be triggered by a specially crafted message during a QUIC session, potentially leading to memory corruption.

Impact

Exploitation of this vulnerability can result in a heap-buffer overflow, which may allow for arbitrary code execution or cause a denial-of-service condition by crashing the application.

Reproduction

The vulnerability can be reproduced by sending a specially crafted message during a QUIC session while using an affected version of the mvfst library. This can be done by creating a QUIC connection and transmitting a message that exploits the heap-buffer-overflow vulnerability, such as one that exceeds the buffer's capacity.

Remediation

Users can upgrade to mvfst version v2025.07.07.00 or later to address this vulnerability.