AIKIDO-2026-139190

coreutils is vulnerable to Incorrect Permission Assignment

GHSA-54x6-c4c8-44frPublished Sep 21, 2026

CVE Score

Medium

Incorrect Permission Assignment

TL;DR

install's fd-based copy path, reached by install -D, opens the destination with O_CREAT|O_WRONLY|O_TRUNC and a default mode of 0666, unlike the path-based copy which opens with O_EXCL and mode 0600. A request such as install -m 600 secret.key /etc/... therefore briefly creates the file group/world readable under the process umask before the trailing chmod narrows it, so another local user can read the content during that window. The same fd path also unlinks the target before recreating it, opening a hard-link planting race. The fix routes the fd-based copy through the same private, exclusive creation already used by the path-based copy.

How do I fix this?

Upgrade the coreutils library to the patch version.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range and you run install -D (or another form that uses the fd-based copy path) to place a file with a restrictive mode on a host with other local users.