BREW-GITLINT-CVE-2026-54552 (GHSA-Q38V-WP89-2W55)
Vulnerability from osv_homebrew – Published: 2026-08-13 16:51 – Updated: 2026-09-17 17:31 – Source websiteImpact
The _uid option performed an incomplete privilege drop on Linux/Unix-like systems.
When sh was run from a process with elevated privileges, such as root, and a command was launched with _uid=<unprivileged user>, the child process changed its UID and primary GID but did not reset its supplementary groups. As a result, the child process could retain the parent process’s supplementary groups, potentially including privileged groups such as root, docker, disk, shadow, or sudo.
This could allow a subprocess that was expected to run with reduced privileges to access files or resources available to the original process’s supplementary groups. Users are impacted if they rely on _uid as a privilege boundary when launching commands from a privileged parent process.
Patches
Upgrade to version >= 2.2.4
Workarounds
Avoid using _uid when the user represents a less-privileged user.
{
"affected": [
{
"ecosystem_specific": {
"fix": "bump",
"range_state": "fixed",
"resource": "sh",
"resource_purl": "pkg:pypi/sh@2.3.0",
"upstream_fixed_in": "2.2.4"
},
"package": {
"ecosystem": "Homebrew",
"name": "gitlint",
"purl": "pkg:brew/gitlint"
},
"ranges": [
{
"events": [
{
"introduced": "0.14.0"
},
{
"fixed": "0.19.1_1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"database_specific": {
"confidence": "high",
"source": "matched",
"strategy": "registry",
"upstream_evidence": [
{
"ecosystem": "PyPI",
"key": "pkg:pypi/sh@2.3.0",
"name": "sh",
"resource": "sh",
"strategy": "registry",
"subject_version": "2.3.0"
}
]
},
"details": "### Impact\nThe `_uid` option performed an incomplete privilege drop on Linux/Unix-like systems.\n\nWhen `sh` was run from a process with elevated privileges, such as root, and a command was launched with `_uid=\u003cunprivileged user\u003e`, the child process changed its UID and primary GID but did not reset its supplementary groups. As a result, the child process could retain the parent process\u2019s supplementary groups, potentially including privileged groups such as root, docker, disk, shadow, or sudo.\n\nThis could allow a subprocess that was expected to run with reduced privileges to access files or resources available to the original process\u2019s supplementary groups. Users are impacted if they rely on `_uid` as a privilege boundary when launching commands from a privileged parent process.\n\n### Patches\nUpgrade to version \u003e= 2.2.4\n\n### Workarounds\nAvoid using `_uid` when the user represents a less-privileged user.",
"id": "BREW-gitlint-CVE-2026-54552",
"modified": "2026-09-17T17:31:02Z",
"published": "2026-08-13T16:51:23Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/amoffat/sh/security/advisories/GHSA-q38v-wp89-2w55"
},
{
"type": "PACKAGE",
"url": "https://github.com/amoffat/sh"
},
{
"type": "WEB",
"url": "https://github.com/amoffat/sh/releases/tag/2.2.4"
}
],
"schema_version": "1.7.3",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "sh _uid does not drop supplementary groups (incomplete privilege drop)",
"upstream": [
"GHSA-q38v-wp89-2w55",
"CVE-2026-54552",
"PYSEC-2026-3540"
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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