UnratedFix available
google-guest-agent, google-osconfig-agent vulnerability
Type: advisorySources: OSV
It was discovered that the Go x/net/idna package, vendored in Google Guest Agent and Google OS Config Agent, incorrectly accepted Punycode-encoded labels that decoded to ASCII-only labels when processing internationalized domain names. A remote attacker could possibly use this issue to bypass hostname-based access controls and escalate privileges.
- Products
- google-guest-agent, google-osconfig-agent
- Affected versions
- 20210608.1-0ubuntu1, 20210608.1-0ubuntu2, 20210608.1-0ubuntu3, 20210629.00-0ubuntu1, 20210629.00-0ubuntu2, 20220104.00-0ubuntu1, 20220104.00-0ubuntu2, 20220622.00-0ubuntu2~22.04.0, 20220622.00-0ubuntu2~22.04.1, 20220824.00-0ubuntu1~22.04.1, 20220824.00-0ubuntu1~22.04.2, 20230426.00-0ubuntu2~22.04.0, 20230504.00-0ubuntu1~22.04.0, 20230504.00-0ubuntu1~22.04.1, 20231004.02-0ubuntu1~22.04.1, 20231004.02-0ubuntu1~22.04.2, 20231004.02-0ubuntu1~22.04.3, 20231004.02-0ubuntu1~22.04.4, 20231004.02-0ubuntu1~22.04.5, 20240320.00-0ubuntu1~22.04.0, 20240320.00-0ubuntu1~22.04.1, 20240524.03-0ubuntu2~22.04.0, 20240524.03-0ubuntu2~22.04.1, 20240716.00-0ubuntu1~22.04.0, 20240926.03-0ubuntu1~22.04.0, 20241011.01-0ubuntu1~22.04.0, 20250115.01-0ubuntu1~22.04.0, 20250116.00-0ubuntu1~22.04.0, 20250116.00-0ubuntu1~22.04.1, 20250116.00-0ubuntu1~22.04.2, 20250116.00-0ubuntu1~22.04.3, 20251028.00-0ubuntu2~22.04.0
- Fixed versions
- 20250116.00-0ubuntu1~22.04.4, 20251028.00-0ubuntu2~22.04.1
- CVEs
- CVE-2026-39821
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 08:49 UTC · Revision 1
Source evidence
google-guest-agent, google-osconfig-agent vulnerability
core-osv · Original sourcePublished 12 Oct 2026, 15:24 UTC
It was discovered that the Go x/net/idna package, vendored in Google Guest Agent and Google OS Config Agent, incorrectly accepted Punycode-encoded labels that decoded to ASCII-only labels when processing internationalized domain names. A remote attacker could possibly use this issue to bypass hostname-based access controls and escalate privileges.
osv:USN-8914-1
google-guest-agent
Fixed versions: 20250116.00-0ubuntu1~22.04.4
google-osconfig-agent
Fixed versions: 20251028.00-0ubuntu2~22.04.1
Complete source record
{
"id": "da90f31c3e371a38b5cdbd00aadbb7eab2008d7a5b6f7becf5f7fc119ab2b2a7",
"url": "https://osv.dev/vulnerability/USN-8914-1",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "google-guest-agent, google-osconfig-agent vulnerability",
"summary": "It was discovered that the Go x/net/idna package, vendored in Google Guest Agent and Google OS Config Agent, incorrectly accepted Punycode-encoded labels that decoded to ASCII-only labels when processing internationalized domain names. A remote attacker could possibly use this issue to bypass hostname-based access controls and escalate privileges.",
"evidence": "osv:USN-8914-1",
"products": [
{
"name": {
"value": "google-guest-agent",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "20250116.00-0ubuntu1~22.04.4",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "20210629.00-0ubuntu1",
"evidence": "/affected/0/versions"
},
{
"value": "20210629.00-0ubuntu2",
"evidence": "/affected/0/versions"
},
{
"value": "20220104.00-0ubuntu1",
"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
"value": "20231004.02-0ubuntu1~22.04.2",
"evidence": "/affected/0/versions"
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{
"value": "20231004.02-0ubuntu1~22.04.3",
"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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{
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{
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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},
{
"name": {
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"evidence": "/affected/1/package/name"
},
"prerequisites": [],
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{
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"evidence": "/affected/1/ranges"
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"affected_versions": [
{
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"evidence": "/affected/1/versions"
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{
"value": "20210608.1-0ubuntu2",
"evidence": "/affected/1/versions"
},
{
"value": "20210608.1-0ubuntu3",
"evidence": "/affected/1/versions"
},
{
"value": "20220824.00-0ubuntu1~22.04.1",
"evidence": "/affected/1/versions"
},
{
"value": "20220824.00-0ubuntu1~22.04.2",
"evidence": "/affected/1/versions"
},
{
"value": "20230504.00-0ubuntu1~22.04.0",
"evidence": "/affected/1/versions"
},
{
"value": "20230504.00-0ubuntu1~22.04.1",
"evidence": "/affected/1/versions"
},
{
"value": "20240320.00-0ubuntu1~22.04.0",
"evidence": "/affected/1/versions"
},
{
"value": "20240320.00-0ubuntu1~22.04.1",
"evidence": "/affected/1/versions"
},
{
"value": "20240524.03-0ubuntu2~22.04.0",
"evidence": "/affected/1/versions"
},
{
"value": "20240524.03-0ubuntu2~22.04.1",
"evidence": "/affected/1/versions"
},
{
"value": "20240926.03-0ubuntu1~22.04.0",
"evidence": "/affected/1/versions"
},
{
"value": "20250115.01-0ubuntu1~22.04.0",
"evidence": "/affected/1/versions"
},
{
"value": "20251028.00-0ubuntu2~22.04.0",
"evidence": "/affected/1/versions"
}
]
}
],
"severity": "unknown",
"structured": {
"id": "USN-8914-1",
"aliases": [
"USN-8914-1"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "20250116.00-0ubuntu1~22.04.4"
}
]
}
],
"package": {
"name": "google-guest-agent",
"purl": "pkg:deb/ubuntu/google-guest-agent?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"20210629.00-0ubuntu1",
"20210629.00-0ubuntu2",
"20220104.00-0ubuntu1",
"20220104.00-0ubuntu2",
"20220622.00-0ubuntu2~22.04.0",
"20220622.00-0ubuntu2~22.04.1",
"20230426.00-0ubuntu2~22.04.0",
"20231004.02-0ubuntu1~22.04.1",
"20231004.02-0ubuntu1~22.04.2",
"20231004.02-0ubuntu1~22.04.3",
"20231004.02-0ubuntu1~22.04.4",
"20231004.02-0ubuntu1~22.04.5",
"20240716.00-0ubuntu1~22.04.0",
"20241011.01-0ubuntu1~22.04.0",
"20250116.00-0ubuntu1~22.04.0",
"20250116.00-0ubuntu1~22.04.1",
"20250116.00-0ubuntu1~22.04.2",
"20250116.00-0ubuntu1~22.04.3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8914-1.json",
"cves_map": {
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{
"id": "CVE-2026-39821",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N"
},
{
"type": "Ubuntu",
"score": "high"
}
]
}
],
"ecosystem": "Ubuntu:22.04:LTS"
}
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "google-guest-agent",
"binary_version": "20250116.00-0ubuntu1~22.04.4"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "20251028.00-0ubuntu2~22.04.1"
}
]
}
],
"package": {
"name": "google-osconfig-agent",
"purl": "pkg:deb/ubuntu/google-osconfig-agent?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"20210608.1-0ubuntu1",
"20210608.1-0ubuntu2",
"20210608.1-0ubuntu3",
"20220824.00-0ubuntu1~22.04.1",
"20220824.00-0ubuntu1~22.04.2",
"20230504.00-0ubuntu1~22.04.0",
"20230504.00-0ubuntu1~22.04.1",
"20240320.00-0ubuntu1~22.04.0",
"20240320.00-0ubuntu1~22.04.1",
"20240524.03-0ubuntu2~22.04.0",
"20240524.03-0ubuntu2~22.04.1",
"20240926.03-0ubuntu1~22.04.0",
"20250115.01-0ubuntu1~22.04.0",
"20251028.00-0ubuntu2~22.04.0"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8914-1.json",
"cves_map": {
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{
"id": "CVE-2026-39821",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N"
},
{
"type": "Ubuntu",
"score": "high"
}
]
}
],
"ecosystem": "Ubuntu:22.04:LTS"
}
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "google-osconfig-agent",
"binary_version": "20251028.00-0ubuntu2~22.04.1"
}
],
"availability": "No subscription required"
}
}
],
"modified": "2026-10-12T20:28:08.148885684Z",
"provider": "osv",
"upstream": [
"CVE-2026-39821",
"UBUNTU-CVE-2026-39821"
],
"references": [
"https://ubuntu.com/security/notices/USN-8914-1",
"https://ubuntu.com/security/CVE-2026-39821"
]
},
"related_cves": [
{
"value": "CVE-2026-39821",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 306757,
"published_at": "2026-10-12T15:24:07+00:00"
}