CVE-2026-40556 - Insecure Directory Permissions in GNU nano Leading to Privilege Abuse

CVE-2026-40556 - Insecure Directory Permissions in GNU nano Leading to Privilege Abuse

https://cvefeed.io/rssfeed/latest.atom / Tue, 04/28/2026 - 20:21
CVE ID :CVE-2026-40556
Published : April 28, 2026, 3:16 p.m. | 2 hours, 58 minutes ago
Description :GNU nano creates the user’s ~/.local directory with overly permissive permissions when the directory does not exist yet. On first use of features requiring Cross-Desktop Group (XDG) data storage, nano explicitly requests directory mode 0777, making the directory world‑writable in environments where the process umask does not sufficiently restrict permissions. In systems with a relaxed or zero umask, such as container environments, CI/CD runners, embedded systems, or user shells configured with umask 000, this results in ~/.local being created as world‑writable. A local attacker can exploit a race window between nano’s creation of ~/.local and its subsequent creation of more restrictive subdirectories to write attacker‑controlled files into the victim’s XDG directory hierarchy. This problem was fixed in nano version 9.0
Severity: 2.1 | LOW
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