usn-8268-1
Vulnerability from osv_ubuntu
Published
2026-05-12 09:23
Modified
2026-06-30 15:55
Summary
dnsmasq vulnerabilities
Details
Andrew S. Fasano, Royce M, and Hugo Martinez Ray discovered that Dnsmasq did not allocate the necessary space to store domain names in some contexts. An attacker could possibly use this issue to write out-of-bounds, and could cause a denial of service or execute arbitrary code. (CVE-2026-2291)
Royce M discovered that Dnsmasq could loop infinitely due to erroneously missing the window header. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-4890)
Royce M discovered that a maliciously crafted packet could cause Dnsmasq to report a negative length. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-4891)
Royce M and Asim Viladi Oglu Manizada discovered that certain configurations of Dnsmasq could write over the DHCPv6 CLID buffer within a privileged helper. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-4892)
Royce M discovered that certain configurations of Dnsmasq could bypass internal bounds checks. An attacker could possibly use this issue to permit malformed packets, and could cause a denial of service. (CVE-2026-4893)
Hugo Martinez discovered that Dnsmasq did not check the rdlen element of a record. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-5172)
References
{
"affected": [
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-2291",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4892",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4893",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:14.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "dnsmasq",
"binary_version": "2.68-1ubuntu0.2+esm5"
},
{
"binary_name": "dnsmasq-base",
"binary_version": "2.68-1ubuntu0.2+esm5"
},
{
"binary_name": "dnsmasq-utils",
"binary_version": "2.68-1ubuntu0.2+esm5"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:14.04:LTS",
"name": "dnsmasq",
"purl": "pkg:deb/ubuntu/dnsmasq@2.68-1ubuntu0.2+esm5?arch=source\u0026distro=esm-infra-legacy/trusty"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.68-1ubuntu0.2+esm5"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.66-4ubuntu1",
"2.67-1",
"2.68-1",
"2.68-1ubuntu0.1",
"2.68-1ubuntu0.2",
"2.68-1ubuntu0.2+esm1",
"2.68-1ubuntu0.2+esm2",
"2.68-1ubuntu0.2+esm3"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-2291",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4890",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4891",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4892",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4893",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-5172",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:16.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "dnsmasq",
"binary_version": "2.90-0ubuntu0.16.04.1+esm3"
},
{
"binary_name": "dnsmasq-base",
"binary_version": "2.90-0ubuntu0.16.04.1+esm3"
},
{
"binary_name": "dnsmasq-base-lua",
"binary_version": "2.90-0ubuntu0.16.04.1+esm3"
},
{
"binary_name": "dnsmasq-utils",
"binary_version": "2.90-0ubuntu0.16.04.1+esm3"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:16.04:LTS",
"name": "dnsmasq",
"purl": "pkg:deb/ubuntu/dnsmasq@2.90-0ubuntu0.16.04.1+esm3?arch=source\u0026distro=esm-infra/xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.90-0ubuntu0.16.04.1+esm3"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.75-1",
"2.75-1ubuntu0.16.04.1",
"2.75-1ubuntu0.16.04.2",
"2.75-1ubuntu0.16.04.3",
"2.75-1ubuntu0.16.04.4",
"2.75-1ubuntu0.16.04.5",
"2.75-1ubuntu0.16.04.7",
"2.75-1ubuntu0.16.04.8",
"2.75-1ubuntu0.16.04.10",
"2.75-1ubuntu0.16.04.10+esm1",
"2.79-1ubuntu0.16.04.1+esm1",
"2.79-1ubuntu0.16.04.1+esm2",
"2.90-0ubuntu0.16.04.1+esm1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-2291",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4890",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4891",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4892",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4893",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-5172",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:18.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "dnsmasq",
"binary_version": "2.90-0ubuntu0.18.04.1+esm3"
},
{
"binary_name": "dnsmasq-base",
"binary_version": "2.90-0ubuntu0.18.04.1+esm3"
},
{
"binary_name": "dnsmasq-base-lua",
"binary_version": "2.90-0ubuntu0.18.04.1+esm3"
},
{
"binary_name": "dnsmasq-utils",
"binary_version": "2.90-0ubuntu0.18.04.1+esm3"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:18.04:LTS",
"name": "dnsmasq",
"purl": "pkg:deb/ubuntu/dnsmasq@2.90-0ubuntu0.18.04.1+esm3?arch=source\u0026distro=esm-infra/bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.90-0ubuntu0.18.04.1+esm3"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.78-1",
"2.78-3",
"2.79-1",
"2.79-1ubuntu0.2",
"2.79-1ubuntu0.3",
"2.79-1ubuntu0.4",
"2.79-1ubuntu0.5",
"2.79-1ubuntu0.6",
"2.79-1ubuntu0.7",
"2.90-0ubuntu0.18.04.1+esm1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-2291",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4890",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4891",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4892",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4893",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-5172",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:20.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "dnsmasq",
"binary_version": "2.90-0ubuntu0.20.04.1+esm2"
},
{
"binary_name": "dnsmasq-base",
"binary_version": "2.90-0ubuntu0.20.04.1+esm2"
},
{
"binary_name": "dnsmasq-base-lua",
"binary_version": "2.90-0ubuntu0.20.04.1+esm2"
},
{
"binary_name": "dnsmasq-utils",
"binary_version": "2.90-0ubuntu0.20.04.1+esm2"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:20.04:LTS",
"name": "dnsmasq",
"purl": "pkg:deb/ubuntu/dnsmasq@2.90-0ubuntu0.20.04.1+esm2?arch=source\u0026distro=esm-infra/focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.90-0ubuntu0.20.04.1+esm2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.80-1ubuntu2",
"2.80-1ubuntu4",
"2.80-1.1ubuntu1",
"2.80-1.1ubuntu1.2",
"2.80-1.1ubuntu1.3",
"2.80-1.1ubuntu1.4",
"2.80-1.1ubuntu1.5",
"2.80-1.1ubuntu1.6",
"2.80-1.1ubuntu1.7",
"2.90-0ubuntu0.20.04.1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-2291",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4890",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4891",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4892",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4893",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-5172",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:22.04:LTS"
}
},
"ecosystem_specific": {
"availability": "No subscription required",
"binaries": [
{
"binary_name": "dnsmasq",
"binary_version": "2.90-0ubuntu0.22.04.3"
},
{
"binary_name": "dnsmasq-base",
"binary_version": "2.90-0ubuntu0.22.04.3"
},
{
"binary_name": "dnsmasq-base-lua",
"binary_version": "2.90-0ubuntu0.22.04.3"
},
{
"binary_name": "dnsmasq-utils",
"binary_version": "2.90-0ubuntu0.22.04.3"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "dnsmasq",
"purl": "pkg:deb/ubuntu/dnsmasq@2.90-0ubuntu0.22.04.3?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.90-0ubuntu0.22.04.3"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.85-1ubuntu2",
"2.86-1.1",
"2.86-1.1ubuntu0.1",
"2.86-1.1ubuntu0.2",
"2.86-1.1ubuntu0.3",
"2.86-1.1ubuntu0.4",
"2.86-1.1ubuntu0.5",
"2.90-0ubuntu0.22.04.1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-2291",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4890",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4891",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4892",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4893",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-5172",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:24.04:LTS"
}
},
"ecosystem_specific": {
"availability": "No subscription required",
"binaries": [
{
"binary_name": "dnsmasq",
"binary_version": "2.90-2ubuntu0.3"
},
{
"binary_name": "dnsmasq-base",
"binary_version": "2.90-2ubuntu0.3"
},
{
"binary_name": "dnsmasq-base-lua",
"binary_version": "2.90-2ubuntu0.3"
},
{
"binary_name": "dnsmasq-utils",
"binary_version": "2.90-2ubuntu0.3"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "dnsmasq",
"purl": "pkg:deb/ubuntu/dnsmasq@2.90-2ubuntu0.3?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.90-2ubuntu0.3"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.89-1",
"2.90-2",
"2.90-2build1",
"2.90-2build2",
"2.90-2ubuntu0.1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-2291",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4890",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4891",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4892",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4893",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-5172",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:25.10"
}
},
"ecosystem_specific": {
"availability": "No subscription required",
"binaries": [
{
"binary_name": "dnsmasq",
"binary_version": "2.91-1ubuntu0.2"
},
{
"binary_name": "dnsmasq-base",
"binary_version": "2.91-1ubuntu0.2"
},
{
"binary_name": "dnsmasq-base-lua",
"binary_version": "2.91-1ubuntu0.2"
},
{
"binary_name": "dnsmasq-utils",
"binary_version": "2.91-1ubuntu0.2"
}
]
},
"package": {
"ecosystem": "Ubuntu:25.10",
"name": "dnsmasq",
"purl": "pkg:deb/ubuntu/dnsmasq@2.91-1ubuntu0.2?arch=source\u0026distro=questing"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.91-1ubuntu0.2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.91-1",
"2.91-1build1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-2291",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4890",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4891",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4892",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-4893",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
},
{
"id": "CVE-2026-5172",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:26.04:LTS"
}
},
"ecosystem_specific": {
"availability": "No subscription required",
"binaries": [
{
"binary_name": "dnsmasq",
"binary_version": "2.92-1ubuntu0.2"
},
{
"binary_name": "dnsmasq-base",
"binary_version": "2.92-1ubuntu0.2"
},
{
"binary_name": "dnsmasq-base-lua",
"binary_version": "2.92-1ubuntu0.2"
},
{
"binary_name": "dnsmasq-utils",
"binary_version": "2.92-1ubuntu0.2"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "dnsmasq",
"purl": "pkg:deb/ubuntu/dnsmasq@2.92-1ubuntu0.2?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.92-1ubuntu0.2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.91-1build1",
"2.92~rc3-1",
"2.92-1"
]
}
],
"aliases": [],
"details": "Andrew S. Fasano, Royce M, and Hugo Martinez Ray discovered that Dnsmasq\ndid not allocate the necessary space to store domain names in some\ncontexts. An attacker could possibly use this issue to write\nout-of-bounds, and could cause a denial of service or execute arbitrary\ncode. (CVE-2026-2291)\n\nRoyce M discovered that Dnsmasq could loop infinitely due to erroneously\nmissing the window header. An attacker could possibly use this issue to\ncause a denial of service. This issue only affected Ubuntu 16.04 LTS,\nUbuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS,\nUbuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-4890)\n\nRoyce M discovered that a maliciously crafted packet could cause Dnsmasq\nto report a negative length. An attacker could possibly use this issue\nto cause a denial of service. This issue only affected Ubuntu 16.04 LTS,\nUbuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS,\nUbuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-4891)\n\nRoyce M and Asim Viladi Oglu Manizada discovered that certain\nconfigurations of Dnsmasq could write over the DHCPv6 CLID buffer within\na privileged helper. An attacker could possibly use this issue to cause\na denial of service or execute arbitrary code. (CVE-2026-4892)\n\nRoyce M discovered that certain configurations of Dnsmasq could bypass\ninternal bounds checks. An attacker could possibly use this issue to\npermit malformed packets, and could cause a denial of service.\n(CVE-2026-4893)\n\nHugo Martinez discovered that Dnsmasq did not check the rdlen element of\na record. An attacker could possibly use this issue to cause a denial of\nservice. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS,\nUbuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.10, and\nUbuntu 26.04 LTS. (CVE-2026-5172)",
"id": "USN-8268-1",
"modified": "2026-06-30T15:55:18Z",
"published": "2026-05-12T09:23:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://ubuntu.com/security/notices/USN-8268-1"
},
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-2291"
},
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-4890"
},
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-4891"
},
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-4892"
},
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-4893"
},
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-5172"
}
],
"related": [],
"schema_version": "1.7.0",
"summary": "dnsmasq vulnerabilities",
"upstream": [
"UBUNTU-CVE-2026-2291",
"UBUNTU-CVE-2026-4890",
"UBUNTU-CVE-2026-4891",
"UBUNTU-CVE-2026-4892",
"UBUNTU-CVE-2026-4893",
"UBUNTU-CVE-2026-5172"
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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