kas — security advisory
kas is a setup tool for bitbake based projects. Prior to 5.4, internal SSH key setup triggered by SSH_PRIVATE_KEY or SSH_PRIVATE_KEY_FILE creates ~/.ssh/config when no user-specific SSH configuration exists and adds a global Host * rule containing StrictHostKeyChecking no. In kas/libcmds.py, ssh_no_host_key_check() runs without checking ctx.managed_env, so the setting persists after kas exits and affects future SSH sessions by the same local user, extending beyond the intended short-lived continuous integration environment. A later SSH connection can therefore accept an attacker-controlled host key without verification, increasing the risk of a man-in-the-middle attack that compromises session confidentiality or integrity. This issue is fixed in version 5.4.
- Products
- kas
- Affected versions
- 2.3.3-2, 2.5-1, 2.6.3-2, 4.0-1, 4.7-1, 4.8.1-1, 4.8.1-2, 5.0-1, 5.1-1, 5.2-1, 5.4-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-54548
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:46 UTC · Revision 1
Source evidence
kas is a setup tool for bitbake based projects. Prior to 5.4, internal SSH key setup triggered by SSH_PRIVATE_KEY or SSH_PRIVATE_KEY_FILE creates ~/.ssh/config when no user-specific SSH configuration exists and adds a global Host * rule containing StrictHostKeyChecking no. In kas/libcmds.py, ssh_no_host_key_check() runs without checking ctx.managed_env, so the setting persists after kas exits and affects future SSH sessions by the same local user, extending beyond the intended short-lived continuous integration environment. A later SSH connection can therefore accept an attacker-controlled host key without verification, increasing the risk of a man-in-the-middle attack that compromises session confidentiality or integrity. This issue is fixed in version 5.4.
osv:UBUNTU-CVE-2026-54548
kas
Fixed versions: Not specified
kas
Fixed versions: Not specified
kas
Fixed versions: Not specified
kas
Fixed versions: Not specified
kas
Fixed versions: Not specified
Complete source record
{
"id": "3cf1fcb5cf7dea8e3534caa66e49bedee225a2b1b5b3acdaa6e8987bdc8578fb",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-54548",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-54548",
"summary": "kas is a setup tool for bitbake based projects. Prior to 5.4, internal SSH key setup triggered by SSH_PRIVATE_KEY or SSH_PRIVATE_KEY_FILE creates ~/.ssh/config when no user-specific SSH configuration exists and adds a global Host * rule containing StrictHostKeyChecking no. In kas/libcmds.py, ssh_no_host_key_check() runs without checking ctx.managed_env, so the setting persists after kas exits and affects future SSH sessions by the same local user, extending beyond the intended short-lived continuous integration environment. A later SSH connection can therefore accept an attacker-controlled host key without verification, increasing the risk of a man-in-the-middle attack that compromises session confidentiality or integrity. This issue is fixed in version 5.4.",
"evidence": "osv:UBUNTU-CVE-2026-54548",
"products": [
{
"name": {
"value": "kas",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.3.3-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.5-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.6.3-2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "kas",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.0-1",
"evidence": "/affected/1/versions"
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{
"name": {
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},
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{
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"evidence": "/affected/2/versions"
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{
"value": "4.8.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.8.1-2",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "kas",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "5.2-1",
"evidence": "/affected/3/versions"
},
{
"value": "5.4-1",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
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"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.8.1-2",
"evidence": "/affected/4/versions"
},
{
"value": "5.0-1",
"evidence": "/affected/4/versions"
},
{
"value": "5.1-1",
"evidence": "/affected/4/versions"
}
]
}
],
"severity": "low",
"structured": {
"id": "UBUNTU-CVE-2026-54548",
"aliases": [
"UBUNTU-CVE-2026-54548"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "kas",
"purl": "pkg:deb/ubuntu/kas?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"2.3.3-2",
"2.5-1",
"2.6.3-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "kas",
"binary_version": "2.6.3-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "kas",
"purl": "pkg:deb/ubuntu/kas?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"4.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54548.json"
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{
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"package": {
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"ecosystem": "Ubuntu:25.10"
},
"versions": [
"4.7-1",
"4.8.1-1",
"4.8.1-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54548.json"
},
"ecosystem_specific": {
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{
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],
"package": {
"name": "kas",
"purl": "pkg:deb/ubuntu/kas?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"5.1-1",
"5.2-1",
"5.4-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "kas",
"binary_version": "5.4-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "kas",
"purl": "pkg:deb/ubuntu/kas?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
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"5.0-1",
"5.1-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "kas",
"binary_version": "5.1-1"
}
]
}
}
],
"modified": "2026-10-17T12:59:06.425154024Z",
"provider": "osv",
"upstream": [
"CVE-2026-54548"
],
"references": [
"https://ubuntu.com/security/CVE-2026-54548",
"https://www.cve.org/CVERecord?id=CVE-2026-54548",
"https://github.com/siemens/kas/security/advisories/GHSA-mv8m-v9v6-5f94"
]
},
"related_cves": [
{
"value": "CVE-2026-54548",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 359299,
"published_at": "2026-08-26T15:16:00+00:00"
}