MNBSD-2026-5: Stack overflow via select() file descriptor set overflow

Severity: Unknown

Affected Package: libnv

Summary: Stack overflow via select() file descriptor set overflow

Description

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 Versions

libnv

Recommendations

No specific recommendations provided.

References

Additional Information

Aliases: CVE-2026-39457

Published: April 29, 2026
Last Modified: April 29, 2026