CVE-2026-49420

CVE-2026-49420 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. The RTSP handler in libalias rewrote outgoing packets into a fixed-length stack buffer without checking whether the rewritten data fit in the buffer, or whether the result fit back in the original packet. A host sending crafted RTSP traffic from inside a NAT gateway using libalias can overflow a stack buffer, potentially achieving remote code execution in the kernel (when using ipfw(4) NAT) or in the natd(8) process (which generally runs as the root user).. EPSS estimates a 0.27% chance of exploitation in the next 30 days.