High
crun — security advisory
A flaw was found in crun. When crun is built with libkrun and a container is started rootful with passt networking (krun.use_passt), crun can execute attacker-controlled payload from the container image with host root privileges. The issue is a regression in crun 1.29. It affects crun >= 1.29
- Products
- crun
- Affected versions
- 0.10.5+dfsg-1, 0.10.6+dfsg-1, 0.11+dfsg-1, 0.12+dfsg-1, 0.12.1+dfsg-1, 0.17+dfsg-1, 0.17+dfsg-1.1, 0.17+dfsg-1.1ubuntu0.1, 1.11-1, 1.11.1-1, 1.12-1, 1.13-1, 1.14-1, 1.14.1-1, 1.21-1ubuntu2, 1.21-1ubuntu3, 1.8.5-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-84042
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:22 UTC · Revision 1
Source evidence
A flaw was found in crun. When crun is built with libkrun and a container is started rootful with passt networking (krun.use_passt), crun can execute attacker-controlled payload from the container image with host root privileges. The issue is a regression in crun 1.29. It affects crun >= 1.29
osv:UBUNTU-CVE-2026-84042
crun
Fixed versions: Not specified
crun
Fixed versions: Not specified
crun
Fixed versions: Not specified
crun
Fixed versions: Not specified
crun
Fixed versions: Not specified
Complete source record
{
"id": "c031ce7ab2e73405d2ea027640bdfcbf6c344266e2c4911f31f3cfcdf66181b3",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-84042",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-84042",
"summary": "A flaw was found in crun. When crun is built with libkrun and a container is started rootful with passt networking (krun.use_passt), crun can execute attacker-controlled payload from the container image with host root privileges. The issue is a regression in crun 1.29. It affects crun >= 1.29",
"evidence": "osv:UBUNTU-CVE-2026-84042",
"products": [
{
"name": {
"value": "crun",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.10.5+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "0.10.6+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "0.11+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "0.12+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "0.12.1+dfsg-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "crun",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.17+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "0.17+dfsg-1.1",
"evidence": "/affected/1/versions"
},
{
"value": "0.17+dfsg-1.1ubuntu0.1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "crun",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.8.5-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.11-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.11.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.12-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.13-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.14-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.14.1-1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "crun",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.21-1ubuntu3",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "crun",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.21-1ubuntu2",
"evidence": "/affected/4/versions"
},
{
"value": "1.21-1ubuntu3",
"evidence": "/affected/4/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2026-84042",
"aliases": [
"UBUNTU-CVE-2026-84042"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "crun",
"purl": "pkg:deb/ubuntu/crun?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"0.10.5+dfsg-1",
"0.10.6+dfsg-1",
"0.11+dfsg-1",
"0.12+dfsg-1",
"0.12.1+dfsg-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84042.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "crun",
"binary_version": "0.12.1+dfsg-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "crun",
"purl": "pkg:deb/ubuntu/crun?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"0.17+dfsg-1",
"0.17+dfsg-1.1",
"0.17+dfsg-1.1ubuntu0.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84042.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "crun",
"binary_version": "0.17+dfsg-1.1ubuntu0.1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "crun",
"purl": "pkg:deb/ubuntu/crun?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"1.8.5-1",
"1.11-1",
"1.11.1-1",
"1.12-1",
"1.13-1",
"1.14-1",
"1.14.1-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84042.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "crun",
"binary_version": "1.14.1-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "crun",
"purl": "pkg:deb/ubuntu/crun?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"1.21-1ubuntu3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84042.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "crun",
"binary_version": "1.21-1ubuntu3"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "crun",
"purl": "pkg:deb/ubuntu/crun?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"1.21-1ubuntu2",
"1.21-1ubuntu3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84042.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "crun",
"binary_version": "1.21-1ubuntu3"
}
]
}
}
],
"modified": "2026-10-17T13:01:12.483899821Z",
"provider": "osv",
"upstream": [
"CVE-2026-84042"
],
"references": [
"https://ubuntu.com/security/CVE-2026-84042",
"https://www.cve.org/CVERecord?id=CVE-2026-84042"
]
},
"related_cves": [
{
"value": "CVE-2026-84042",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 361239,
"published_at": "2026-09-10T09:17:00+00:00"
}