CVE-2026-59692 is a stack-based buffer overflow vulnerability in the GStreamer DTLS plugin. During a DTLS handshake, the peer certificate's Subject Distinguished Name is printed into a fixed-size 2048-byte stack buffer without bounds checking. A remote unauthenticated attacker can send a certificate with an oversized Subject DN, causing a stack buffer overflow that leads to a process crash and denial of service. The vulnerability is mitigated against remote code execution because the function X509_NAME_print_ex() escapes binary and control characters to printable ASCII, preventing arbitrary byte injection. Additionally, Red Hat builds include stack canary protection (-fstack-protector-strong), which prevents exploitation of return address corruption. The DTLS plugin is part of gstreamer1-plugins-bad-free used in Red Hat Enterprise Linux versions 8, 9, and 10, and is utilized by GStreamer WebRTC pipelines. Red Hat has released security updates addressing this vulnerability.

The vulnerability allows remote unauthenticated attackers to cause a denial of service by crashing the process during a DTLS handshake via a crafted certificate with an oversized Subject DN. There is no impact on confidentiality or integrity, and remote code execution is not achievable due to escaping of control characters and stack canary protections. The impact is limited to availability (denial of service).

A security update fixing this vulnerability is available from Red Hat and should be applied. If the DTLS plugin or WebRTC/DTLS functionality is not required, removing the DTLS plugin shared object (libgstdtls.so) from the GStreamer plugins directory is recommended. Additionally, restricting network access to WebRTC/DTLS endpoints to trusted peers via firewall rules and deploying GStreamer WebRTC services behind reverse proxies or media servers that validate DTLS certificates before forwarding can reduce risk. There is no complete mitigation other than applying the official fix.