Improper Handling of TMPDIR Environment Variable in Uutils Coreutils

CVE-2026-35342

What is CVE-2026-35342?

The mktemp utility in Uutils Coreutils contains a flaw in its handling of the TMPDIR environment variable. Unlike its GNU counterpart, which defaults to using /tmp when TMPDIR is an empty string, the Uutils implementation incorrectly recognizes the empty string as a valid directory path. This misconfiguration results in the creation of temporary files within the current working directory (CWD). Consequently, if the permissions of the CWD are less restrictive than those of /tmp, this can expose sensitive data to unintended users. As a result, there is a significant risk of unauthorized access to temporary files, highlighting the necessity for proper configuration and secure temporary file handling.

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