CVE-2026-104112: Missing release of passed file descriptors in illumos nscd allows local users to exhaust kernel memory

Severity: medium (CVSS 6.8 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-09 · updated 2026-10-09
Weakness: CWE-772

Description

A missing release of resources in the illumos name service cache daemon (nscd) allows a local user to exhaust kernel memory. The nscd door server procedure, switcher() in usr/src/cmd/nscd/nscd_frontend.c, does not close file descriptors that are passed with a door call but not used by the request, and the main nscd door at /var/run/name_service_door accepts passed descriptors from any user in its zone. Because nscd also runs with an unlimited file descriptor limit, an unprivileged local user, including one in a non-global zone, can repeatedly pass a descriptor to its zone's nscd in a door_call() loop, causing the file descriptor table of nscd to grow without bound in kernel memory. This causes a denial of service of nscd and can render processes in all zones on the host unresponsive. The flaw has existed since 2006 (illumos-gate commit cb5caa98), and affects any illumos distribution prior to illumos-gate commit af810a72.

Affected products

OmniOS: from any before r151054; from r151058 before r151058w; from r151056 before r151056aw; from r151054 before r151054bw — fixed in r151054, r151054bw, r151056aw, r151058w

How to fix

Upgrade to a fixed version: OmniOS r151054, r151054bw, r151056aw, r151058w. Check the vendor advisory for mitigations.

References

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