High
Security advisory
etcd versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 are vulnerable to an improper authentication issue when role-based access control (RBAC) is used and client-cert-auth is enabled. If an etcd client server TLS certificate contains a Common Name (CN) which matches a valid RBAC username, a remote attacker may authenticate as that user with any valid (trusted) client certificate in a REST API request to the gRPC-gateway.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2018-16886
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 10:17 UTC · Revision 1
Source evidence
etcd versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 are vulnerable to an improper authentication issue when role-based access control (RBAC) is used and client-cert-auth is enabled. If an etcd client server TLS certificate contains a Common Name (CN) which matches a valid RBAC username, a remote attacker may authenticate as that user with any valid (trusted) client certificate in a REST API request to the gRPC-gateway.
osv:CVE-2018-16886
Complete source record
{
"id": "63640be11af514a3b9ce3152091f7785ce3e640aad10588c6c80cd26d453e971",
"url": "https://osv.dev/vulnerability/CVE-2018-16886",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2018-16886",
"summary": "etcd versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 are vulnerable to an improper authentication issue when role-based access control (RBAC) is used and client-cert-auth is enabled. If an etcd client server TLS certificate contains a Common Name (CN) which matches a valid RBAC username, a remote attacker may authenticate as that user with any valid (trusted) client certificate in a REST API request to the gRPC-gateway.",
"evidence": "osv:CVE-2018-16886",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2018-16886",
"aliases": [
"CVE-2018-16886",
"GHSA-h6xx-pmxh-3wgp",
"GO-2021-0077"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/etcd-io/etcd",
"type": "GIT",
"events": [
{
"introduced": "e475a4ea710491899fd4427552eda6ee45775320"
},
{
"fixed": "06cec40911744c0aca5d1afd69b2631b0a4879ba"
},
{
"introduced": "c23606781f63d09917a1e7abfcefeb337a9608ea"
},
{
"fixed": "2cf9e51d2a78003b164c2998886158e60ded1cbb"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.2.0"
},
{
"fixed": "3.2.26"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.3.0"
},
{
"fixed": "3.3.11"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v3.3.10",
"v3.3.9",
"v3.3.8",
"v3.3.7",
"v3.3.6",
"v3.3.5",
"v3.3.4",
"v3.3.3",
"v3.3.2",
"v3.3.1",
"v3.3.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-16886.json"
}
}
],
"modified": "2026-10-20T10:50:04.174693627Z",
"provider": "osv",
"references": [
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JX7QTIT465BQGRGNCE74RATRQLKT2QE4/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UPGYHMSKDPW5GAMI7BEP3XQRVRLLBJKS/",
"https://access.redhat.com/errata/RHSA-2019:0237",
"https://access.redhat.com/errata/RHSA-2019:1352",
"https://github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.2.md#security-authentication",
"https://github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.3.md#security-authentication",
"https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16886"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "30"
},
{
"last_affected": "30"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*"
],
"vendor_product": "redhat:enterprise_linux_desktop",
"extracted_events": [
{
"range": [
{
"introduced": "7.0"
},
{
"last_affected": "7.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*"
],
"vendor_product": "redhat:enterprise_linux_server",
"extracted_events": [
{
"range": [
{
"introduced": "7.0"
},
{
"last_affected": "7.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*"
],
"vendor_product": "redhat:enterprise_linux_workstation",
"extracted_events": [
{
"range": [
{
"introduced": "7.0"
},
{
"last_affected": "7.0"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2018-16886",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 381229,
"published_at": "2019-01-14T19:29:00.243+00:00"
}