What’s Vulnerable › Vulnerabilities
CVE-2026-39461: select(2) file descriptor set overflow causes stack overflow
- Severity: high (CVSS 8.8 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: 2026-05-21 · updated 2026-07-23
- Weakness: CWE-121
Description
libcasper(3) communicates with helper processes via UNIX domain sockets, and uses the select(2) system call to wait for data to become available. However, it does not verify that its socket descriptor fits within select(2)'s descriptor set size limit of FD_SETSIZE (1024). An attacker able to cause an application using libcasper(3) to allocate large file descriptors, e.g., by opening many descriptors and executing a program which is not careful to close them upon startup, may trigger stack corruption. If the target application runs with setuid root privileges, this could be used to escalate local privileges.
Affected products
- FreeBSD: 14.3, 14.3-p1, 14.3-p10, 14.3-p11, 14.3-p12, 14.3-p13 (+23)
References
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