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.

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History

Thu, 21 May 2026 11:45:00 +0000

Type Values Removed Values Added
First Time appeared Freebsd
Freebsd freebsd
Vendors & Products Freebsd
Freebsd freebsd

Thu, 21 May 2026 10:15:00 +0000

Type Values Removed Values Added
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.
Title select(2) file descriptor set overflow causes stack overflow
Weaknesses CWE-121
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cve-icon MITRE

Status: PUBLISHED

Assigner: freebsd

Published:

Updated: 2026-05-21T09:20:26.126Z

Reserved: 2026-04-28T15:08:10.637Z

Link: CVE-2026-39461

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-21T10:16:25.320

Modified: 2026-05-21T10:16:25.320

Link: CVE-2026-39461

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-21T11:30:06Z

Weaknesses