CVE-2026-54552 HIGH

CVE-2026-54552: sh _uid does not drop supplementary groups (incomplete privilege drop)

Vendor Amoffat
Product sh
Weakness CWE-273
Published August 18, 2026
Last update August 18, 2026

CVSS base score

7.9/10
Attack vector Local
Attack complexity Low
Privileges required High
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

What the vulnerability does

01Description

sh provides Python process launching. Prior to 2.2.4, the _uid option in sh.py performs an incomplete privilege drop on Linux and Unix-like systems. When sh runs from an elevated process and launches a command with _uid set to an unprivileged user, the child changes its UID but can retain the parent process's supplementary groups because the privilege-drop sequence does not fully establish the target user's UID, primary GID, and supplementary groups. The child can therefore retain access to files or resources granted to privileged groups such as root, docker, disk, shadow, or sudo, violating the expected _uid privilege boundary. This issue is fixed in version 2.2.4.

Key dates

02Disclosure timeline

August 18, 2026 CVE published