UnratedFix available
c-ares vulnerabilities
Type: advisorySources: OSV
It was discovered that c-ares incorrectly parsed certain SOA replies. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2020-22217) It was discovered that c-ares incorrectly handled certain sortlist strings. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service, or execute arbitrary code. This issue only affected Ubuntu 16.04 LTS. (CVE-2022-4904) It was discovered that c-ares did not properly limit DNS compression pointer hops or assembled name lengths when parsing DNS names. A remote attacker could possibly use this issue to cause c-ares to use excessive resources, resulting in a denial of service. (CVE-2026-69184) It was discovered that c-ares did not properly validate record count fields before allocating memory when parsing DNS responses. A remote attacker could possibly use this issue to cause c-ares to use excessive resources, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-69186)
- Products
- c-ares
- Affected versions
- 1.10.0-2, 1.10.0-3, 1.10.0-3ubuntu0.1, 1.10.0-3ubuntu0.2, 1.10.0-3ubuntu0.2+esm1, 1.10.0-3ubuntu0.2+esm2, 1.10.0-3ubuntu0.2+esm3, 1.13.0-2, 1.13.0-3, 1.14.0-1, 1.14.0-1ubuntu0.1, 1.14.0-1ubuntu0.2, 1.14.0-1ubuntu0.2+esm1, 1.14.0-1ubuntu0.2+esm2, 1.15.0-1build1, 1.15.0-1ubuntu0.1, 1.15.0-1ubuntu0.2, 1.15.0-1ubuntu0.3, 1.15.0-1ubuntu0.4, 1.15.0-1ubuntu0.5, 1.17.1-1ubuntu1, 1.18.1-1, 1.18.1-1build1, 1.18.1-1ubuntu0.22.04.1, 1.18.1-1ubuntu0.22.04.2, 1.18.1-1ubuntu0.22.04.3, 1.19.1-3, 1.20.1-1, 1.26.0-1, 1.27.0-1, 1.27.0-1.0ubuntu1, 1.34.5-1, 1.34.6-1, 1.34.6-1ubuntu0.1
- Fixed versions
- 1.10.0-3ubuntu0.2+esm4, 1.14.0-1ubuntu0.2+esm3, 1.15.0-1ubuntu0.5+esm1, 1.18.1-1ubuntu0.22.04.4, 1.27.0-1.0ubuntu1.1, 1.34.6-1ubuntu0.2
- CVEs
- CVE-2020-22217, CVE-2022-4904, CVE-2026-69184, CVE-2026-69186
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 17:41 UTC · Revision 1
Source evidence
It was discovered that c-ares incorrectly parsed certain SOA replies. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2020-22217) It was discovered that c-ares incorrectly handled certain sortlist strings. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service, or execute arbitrary code. This issue only affected Ubuntu 16.04 LTS. (CVE-2022-4904) It was discovered that c-ares did not properly limit DNS compression pointer hops or assembled name lengths when parsing DNS names. A remote attacker could possibly use this issue to cause c-ares to use excessive resources, resulting in a denial of service. (CVE-2026-69184) It was discovered that c-ares did not properly validate record count fields before allocating memory when parsing DNS responses. A remote attacker could possibly use this issue to cause c-ares to use excessive resources, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-69186)
osv:USN-8951-1
c-ares
Fixed versions: 1.10.0-3ubuntu0.2+esm4
c-ares
Fixed versions: 1.14.0-1ubuntu0.2+esm3
c-ares
Fixed versions: 1.15.0-1ubuntu0.5+esm1
c-ares
Fixed versions: 1.18.1-1ubuntu0.22.04.4
c-ares
Fixed versions: 1.27.0-1.0ubuntu1.1
c-ares
Fixed versions: 1.34.6-1ubuntu0.2
Complete source record
{
"id": "8c6de257d4d174a965528ba3161a9bbc7e387cd28839e3cf4eec3a857a75a609",
"url": "https://osv.dev/vulnerability/USN-8951-1",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "c-ares vulnerabilities",
"summary": "It was discovered that c-ares incorrectly parsed certain SOA replies. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2020-22217) It was discovered that c-ares incorrectly handled certain sortlist strings. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service, or execute arbitrary code. This issue only affected Ubuntu 16.04 LTS. (CVE-2022-4904) It was discovered that c-ares did not properly limit DNS compression pointer hops or assembled name lengths when parsing DNS names. A remote attacker could possibly use this issue to cause c-ares to use excessive resources, resulting in a denial of service. (CVE-2026-69184) It was discovered that c-ares did not properly validate record count fields before allocating memory when parsing DNS responses. A remote attacker could possibly use this issue to cause c-ares to use excessive resources, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-69186)",
"evidence": "osv:USN-8951-1",
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{
"value": "1.15.0-1ubuntu0.5",
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{
"name": {
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{
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{
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{
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{
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{
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"name": {
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{
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{
"name": {
"value": "c-ares",
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"fixed_versions": [
{
"value": "1.34.6-1ubuntu0.2",
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],
"affected_versions": [
{
"value": "1.34.5-1",
"evidence": "/affected/5/versions"
},
{
"value": "1.34.6-1",
"evidence": "/affected/5/versions"
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{
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"package": {
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"purl": "pkg:deb/ubuntu/c-ares?arch=source&distro=esm-infra-legacy%2Fxenial",
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},
{
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]
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{
"id": "CVE-2026-69184",
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"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
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]
}
],
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}
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libc-ares2",
"binary_version": "1.10.0-3ubuntu0.2+esm4"
}
],
"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}
},
{
"ranges": [
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],
"package": {
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"1.14.0-1ubuntu0.2+esm1",
"1.14.0-1ubuntu0.2+esm2"
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"id": "CVE-2026-69184",
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{
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"ecosystem_specific": {
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"package": {
"name": "c-ares",
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},
{
"type": "Ubuntu",
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}
],
"ecosystem": "Ubuntu:Pro:20.04:LTS"
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},
"ecosystem_specific": {
"binaries": [
{
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],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
},
{
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]
}
],
"package": {
"name": "c-ares",
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"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"1.17.1-1ubuntu1",
"1.18.1-1",
"1.18.1-1build1",
"1.18.1-1ubuntu0.22.04.1",
"1.18.1-1ubuntu0.22.04.2",
"1.18.1-1ubuntu0.22.04.3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8951-1.json",
"cves_map": {
"cves": [
{
"id": "CVE-2026-69184",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:22.04:LTS"
}
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libc-ares2",
"binary_version": "1.18.1-1ubuntu0.22.04.4"
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],
"availability": "No subscription required"
}
},
{
"ranges": [
{
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{
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{
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]
}
],
"package": {
"name": "c-ares",
"purl": "pkg:deb/ubuntu/c-ares?arch=source&distro=noble",
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},
"versions": [
"1.19.1-3",
"1.20.1-1",
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"1.27.0-1.0ubuntu1"
],
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{
"id": "CVE-2026-69184",
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{
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"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
},
{
"id": "CVE-2026-69186",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "Ubuntu",
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}
]
}
],
"ecosystem": "Ubuntu:24.04:LTS"
}
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcares2",
"binary_version": "1.27.0-1.0ubuntu1.1"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
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{
"introduced": "0"
},
{
"fixed": "1.34.6-1ubuntu0.2"
}
]
}
],
"package": {
"name": "c-ares",
"purl": "pkg:deb/ubuntu/c-ares?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"1.34.5-1",
"1.34.6-1",
"1.34.6-1ubuntu0.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8951-1.json",
"cves_map": {
"cves": [
{
"id": "CVE-2026-69184",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
},
{
"id": "CVE-2026-69186",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:26.04:LTS"
}
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libc-ares2",
"binary_version": "1.34.6-1ubuntu0.2"
},
{
"binary_name": "libcares2",
"binary_version": "1.34.6-1ubuntu0.2"
}
],
"availability": "No subscription required"
}
}
],
"modified": "2026-10-22T04:42:58.035678055Z",
"provider": "osv",
"upstream": [
"CVE-2020-22217",
"CVE-2022-4904",
"CVE-2026-69184",
"CVE-2026-69186",
"UBUNTU-CVE-2020-22217",
"UBUNTU-CVE-2022-4904",
"UBUNTU-CVE-2026-69184",
"UBUNTU-CVE-2026-69186"
],
"references": [
"https://ubuntu.com/security/notices/USN-8951-1",
"https://ubuntu.com/security/CVE-2020-22217",
"https://ubuntu.com/security/CVE-2022-4904",
"https://ubuntu.com/security/CVE-2026-69184",
"https://ubuntu.com/security/CVE-2026-69186"
]
},
"related_cves": [
{
"value": "CVE-2020-22217",
"evidence": "/upstream"
},
{
"value": "CVE-2022-4904",
"evidence": "/upstream"
},
{
"value": "CVE-2026-69184",
"evidence": "/upstream"
},
{
"value": "CVE-2026-69186",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 404341,
"published_at": "2026-10-21T18:20:42+00:00"
}