GHSA-MJCV-P78Q-W5FW
Vulnerability from github – Published: 2026-10-08 16:08 – Updated: 2026-10-08 16:08A denial-of-service (DoS) vulnerability exists in github.com/moby/sys/user before v0.4.1 when parsing specially crafted user or group database files. An attacker able to supply a malicious /etc/passwd or /etc/group-style file may cause excessive memory consumption, potentially resulting in process termination due to Out Of Memory (OOM) conditions.
This issue is related to containerd [CVE-2026-47262] / GHSA-jpcc-p29g-p8mq, which describes one practical exploitation path through processing untrusted container image content. Applications using github.com/moby/sys/user to parse untrusted user or group database files may be similarly affected.
Impact
github.com/moby/sys/user versions before v0.4.1 do not place sufficient limits on entries while parsing user and group database files. A specially crafted file may cause excessive memory consumption, potentially leading to process termination due to Out Of Memory (OOM) conditions.
Applications that use github.com/moby/sys/user to parse user-supplied or otherwise untrusted /etc/passwd or /etc/group files may be affected. The severity depends on whether an attacker can influence the contents of files being parsed.
Patches
This issue is fixed in github.com/moby/sys/user v0.4.1. Users should upgrade to v0.4.1 or later.
Workarounds
Avoid parsing attacker-controlled /etc/passwd or /etc/group-style files with affected versions of github.com/moby/sys/user.
Applications that must process untrusted user or group database files should validate and limit accepted input before parsing. Upgrading to v0.4.1 or later is the recommended remediation.
References
- containerd CVE-2026-47262 / GHSA-jpcc-p29g-p8mq: https://github.com/containerd/containerd/security/advisories/GHSA-jpcc-p29g-p8mq
- Fix in
github.com/moby/sys/user: https://github.com/moby/sys/user/commit/210d32ba2bcb4544ee968c7f31249fe59796e60b
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.4.0"
},
"package": {
"ecosystem": "Go",
"name": "github.com/moby/sys/user"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.4.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-61801"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-08T16:08:33Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "A denial-of-service (DoS) vulnerability exists in `github.com/moby/sys/user` before v0.4.1 when parsing specially crafted user or group database files. An attacker able to supply a malicious `/etc/passwd` or `/etc/group`-style file may cause excessive memory consumption, potentially resulting in process termination due to Out Of Memory (OOM) conditions.\n\nThis issue is related to containerd [CVE-2026-47262] / [GHSA-jpcc-p29g-p8mq](https://github.com/containerd/containerd/security/advisories/GHSA-jpcc-p29g-p8mq), which describes one practical exploitation path through processing untrusted container image content. Applications using `github.com/moby/sys/user` to parse untrusted user or group database files may be similarly affected.\n\n### Impact\n\n`github.com/moby/sys/user` versions before v0.4.1 do not place sufficient limits on entries while parsing user and group database files. A specially crafted file may cause excessive memory consumption, potentially leading to process termination due to Out Of Memory (OOM) conditions.\n\nApplications that use `github.com/moby/sys/user` to parse user-supplied or otherwise untrusted `/etc/passwd` or `/etc/group` files may be affected. The severity depends on whether an attacker can influence the contents of files being parsed.\n\n### Patches\n\nThis issue is fixed in `github.com/moby/sys/user` v0.4.1. Users should upgrade to v0.4.1 or later.\n\n### Workarounds\n\nAvoid parsing attacker-controlled `/etc/passwd` or `/etc/group`-style files with affected versions of `github.com/moby/sys/user`.\n\nApplications that must process untrusted user or group database files should validate and limit accepted input before parsing. Upgrading to v0.4.1 or later is the recommended remediation.\n\n### References\n\n* containerd CVE-2026-47262 / GHSA-jpcc-p29g-p8mq: https://github.com/containerd/containerd/security/advisories/GHSA-jpcc-p29g-p8mq\n* Fix in `github.com/moby/sys/user`: https://github.com/moby/sys/user/commit/210d32ba2bcb4544ee968c7f31249fe59796e60b",
"id": "GHSA-mjcv-p78q-w5fw",
"modified": "2026-10-08T16:08:34Z",
"published": "2026-10-08T16:08:33Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/moby/sys/security/advisories/GHSA-mjcv-p78q-w5fw"
},
{
"type": "WEB",
"url": "https://github.com/moby/sys/pull/221"
},
{
"type": "WEB",
"url": "https://github.com/moby/sys/commit/85a71bbe1faa36c552a960e6a5f3d0cfb632fbbe"
},
{
"type": "PACKAGE",
"url": "https://github.com/moby/sys"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "github.com/moby/sys/user has a possible DoS via unbounded parsing of user and group database files"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- 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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