UBUNTU-CVE-2026-4438

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Source
https://ubuntu.com/security/CVE-2026-4438
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4438.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2026-4438
Upstream
Published
2026-03-20T20:16:00Z
Modified
2026-05-29T19:15:07.531598992Z
Severity
  • 5.4 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.

References

Affected packages

Ubuntu:Pro:14.04:LTS / eglibc

Package

Name
eglibc
Purl
pkg:deb/ubuntu/eglibc?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.17-93ubuntu4
2.18-0ubuntu1
2.18-0ubuntu2
2.18-0ubuntu4
2.18-0ubuntu5
2.18-0ubuntu6
2.18-0ubuntu7
2.19-0ubuntu2
2.19-0ubuntu3
2.19-0ubuntu4
2.19-0ubuntu5
2.19-0ubuntu6
2.19-0ubuntu6.1
2.19-0ubuntu6.3
2.19-0ubuntu6.4
2.19-0ubuntu6.5
2.19-0ubuntu6.6
2.19-0ubuntu6.7
2.19-0ubuntu6.8
2.19-0ubuntu6.9
2.19-0ubuntu6.10
2.19-0ubuntu6.11
2.19-0ubuntu6.13
2.19-0ubuntu6.14
2.19-0ubuntu6.15
2.19-0ubuntu6.15+esm1
2.19-0ubuntu6.15+esm2
2.19-0ubuntu6.15+esm3
2.19-0ubuntu6.15+esm4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "eglibc-source"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc-bin"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc-dev-bin"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-amd64"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-armel"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-dev-amd64"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-dev-armel"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-dev-i386"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-dev-x32"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-i386"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-pic"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-prof"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "libc6-x32"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "multiarch-support"
        },
        {
            "binary_version": "2.19-0ubuntu6.15+esm4",
            "binary_name": "nscd"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4438.json"

Ubuntu:24.04:LTS / glibc

Package

Name
glibc
Purl
pkg:deb/ubuntu/glibc?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.38-1ubuntu6
2.38-3ubuntu1
2.39-0ubuntu1
2.39-0ubuntu2
2.39-0ubuntu6
2.39-0ubuntu8
2.39-0ubuntu8.1
2.39-0ubuntu8.2
2.39-0ubuntu8.3
2.39-0ubuntu8.4
2.39-0ubuntu8.5
2.39-0ubuntu8.6
2.39-0ubuntu8.7

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "glibc-source"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc-bin"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc-dev-bin"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc-devtools"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6-amd64"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6-dev-amd64"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6-dev-i386"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6-dev-s390"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6-dev-x32"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6-i386"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6-s390"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "libc6-x32"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "locales"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "locales-all"
        },
        {
            "binary_version": "2.39-0ubuntu8.7",
            "binary_name": "nscd"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4438.json"

Ubuntu:25.10 / glibc

Package

Name
glibc
Purl
pkg:deb/ubuntu/glibc?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.41-6ubuntu1
2.41-6ubuntu2
2.41-9ubuntu1
2.42-0ubuntu1
2.42-0ubuntu3
2.42-0ubuntu3.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "glibc-source"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc-bin"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc-dev-bin"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc-devtools"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc6"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc6-amd64"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc6-dev-amd64"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc6-dev-i386"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc6-dev-x32"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc6-i386"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "libc6-x32"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "locales"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "locales-all"
        },
        {
            "binary_version": "2.42-0ubuntu3.1",
            "binary_name": "nscd"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4438.json"

Ubuntu:26.04:LTS / glibc

Package

Name
glibc
Purl
pkg:deb/ubuntu/glibc?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.42-0ubuntu3
2.42-2ubuntu1
2.42-2ubuntu2
2.42-2ubuntu4
2.42-2ubuntu5
2.43-2ubuntu1
2.43-2ubuntu2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "glibc-source"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc-bin"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc-dev-bin"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc-devtools"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc-gconv-modules-extra"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc6"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc6-amd64"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc6-dev-amd64"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc6-dev-i386"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc6-dev-x32"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc6-i386"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "libc6-x32"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "locales"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "locales-all"
        },
        {
            "binary_version": "2.43-2ubuntu2",
            "binary_name": "nscd"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4438.json"