What’s Vulnerable › Vulnerabilities
CVE-2026-39457: Stack overflow via select() file descriptor set overflow
- Severity: high (CVSS 7.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-04-30 · updated 2026-06-17
- Weakness: CWE-121
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 products
- FreeBSD: 13.5, 13.5-beta3, 13.5-p1, 13.5-p10, 13.5-p11, 13.5-p12 (+31)
References
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