The `github.com/moby/sys/user` package provides Go utilities for parsing and looking up entries in Unix-style user and group database files. Versions before 0.4.1 do not sufficiently limit entries when parsing `/etc/passwd`- or `/etc/group`-style files, allowing an attacker who can supply a specially crafted file to cause excessive memory consumption and potentially terminate the affected process due to an out-of-memory condition. This issue is patched in version 0.4.1. As a workaround, avoid parsing attacker-controlled user or group database files, or validate and limit untrusted input before parsing it.
https://github.com/moby/sys/security/advisories/GHSA-mjcv-p78q-w5fw
https://github.com/moby/sys/pull/221
https://github.com/moby/sys/commit/85a71bbe1faa36c552a960e6a5f3d0cfb632fbbe
Published: 2026-10-08
Updated: 2026-10-08
Named Vulnerability: GO-2026-6686Named Vulnerability: GHSA-mjcv-p78q-w5fw
Base Score: 4.6
Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C
Severity: Medium
Base Score: 5.5
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity: Medium
EPSS: 0.00117