CVE-2026-39457: Freebsd

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

When exchanging data over a socket, libnv uses select(2) to wait for data to arrive. However, it does not verify whether the provided socket descriptor fits in select(2)'s file descriptor set size limit of FD_SETSIZE (1024). An attacker who is able to force a libnv application to allocate large file descriptors, e.g., by opening many descriptors and executing a program which is not careful to close them upon startup, can trigger stack corruption. If the target application is setuid-root, then this could be used to elevate local privileges.

Affected products

• Freebsd Freebsd: version 13.5 only; version 14.3 only; version 14.4 only; version 15.0 only

Published 2026-04-30. Last modified 2026-06-17.