UBUNTU-CVE-2026-42013

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Source
https://ubuntu.com/security/CVE-2026-42013
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-42013
Upstream
  • CVE-2026-42013
Downstream
Related
Published
2026-04-30T00:00:00Z
Modified
2026-07-14T23:44:41Z
Severity
  • 8.2 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certificate validation, potentially leading to spoofing or man-in-the-middle attacks.

References

Affected packages

Ubuntu:22.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.7.3-4ubuntu1.9

Affected versions

3.*
3.7.1-5ubuntu1
3.7.2-2ubuntu1
3.7.2-4ubuntu1
3.7.2-5ubuntu1
3.7.3-4ubuntu1
3.7.3-4ubuntu1.1
3.7.3-4ubuntu1.2
3.7.3-4ubuntu1.3
3.7.3-4ubuntu1.4
3.7.3-4ubuntu1.5
3.7.3-4ubuntu1.6
3.7.3-4ubuntu1.7
3.7.3-4ubuntu1.8

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.7.3-4ubuntu1.9"
        },
        {
            "binary_name": "guile-gnutls",
            "binary_version": "3.7.3-4ubuntu1.9"
        },
        {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.7.3-4ubuntu1.9"
        },
        {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.7.3-4ubuntu1.9"
        },
        {
            "binary_name": "libgnutls30",
            "binary_version": "3.7.3-4ubuntu1.9"
        },
        {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.7.3-4ubuntu1.9"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:24.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.8.3-1.1ubuntu3.6

Affected versions

3.*
3.8.1-4ubuntu1
3.8.1-4ubuntu6
3.8.1-4ubuntu7
3.8.3-1ubuntu1
3.8.3-1.1ubuntu2
3.8.3-1.1ubuntu3
3.8.3-1.1ubuntu3.1
3.8.3-1.1ubuntu3.2
3.8.3-1.1ubuntu3.3
3.8.3-1.1ubuntu3.4
3.8.3-1.1ubuntu3.5

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.8.3-1.1ubuntu3.6"
        },
        {
            "binary_name": "libgnutls-dane0t64",
            "binary_version": "3.8.3-1.1ubuntu3.6"
        },
        {
            "binary_name": "libgnutls-openssl27t64",
            "binary_version": "3.8.3-1.1ubuntu3.6"
        },
        {
            "binary_name": "libgnutls30t64",
            "binary_version": "3.8.3-1.1ubuntu3.6"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:25.10
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.8.9-3ubuntu2.2

Affected versions

3.*
3.8.9-2ubuntu3
3.8.9-3ubuntu1
3.8.9-3ubuntu2
3.8.9-3ubuntu2.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.8.9-3ubuntu2.2"
        },
        {
            "binary_name": "libgnutls-dane0t64",
            "binary_version": "3.8.9-3ubuntu2.2"
        },
        {
            "binary_name": "libgnutls-openssl27t64",
            "binary_version": "3.8.9-3ubuntu2.2"
        },
        {
            "binary_name": "libgnutls30t64",
            "binary_version": "3.8.9-3ubuntu2.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:26.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.8.12-2ubuntu1.1

Affected versions

3.*
3.8.9-3ubuntu2
3.8.10-3ubuntu1
3.8.12-2ubuntu1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.8.12-2ubuntu1.1"
        },
        {
            "binary_name": "libgnutls-dane0t64",
            "binary_version": "3.8.12-2ubuntu1.1"
        },
        {
            "binary_name": "libgnutls-openssl27t64",
            "binary_version": "3.8.12-2ubuntu1.1"
        },
        {
            "binary_name": "libgnutls30t64",
            "binary_version": "3.8.12-2ubuntu1.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:Pro:16.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=esm-infra-legacy%2Fxenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.4.10-4ubuntu1.9+esm4

Affected versions

3.*
3.3.15-5ubuntu2
3.3.18-1ubuntu1
3.3.20-1ubuntu1
3.4.9-2ubuntu1
3.4.10-4ubuntu1
3.4.10-4ubuntu1.1
3.4.10-4ubuntu1.2
3.4.10-4ubuntu1.3
3.4.10-4ubuntu1.4
3.4.10-4ubuntu1.5
3.4.10-4ubuntu1.6
3.4.10-4ubuntu1.7
3.4.10-4ubuntu1.8
3.4.10-4ubuntu1.9
3.4.10-4ubuntu1.9+esm1
3.4.10-4ubuntu1.9+esm2
3.4.10-4ubuntu1.9+esm3

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
        },
        {
            "binary_name": "guile-gnutls",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
        },
        {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
        },
        {
            "binary_name": "libgnutls30",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
        },
        {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:Pro:18.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=esm-infra%2Fbionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.5.18-1ubuntu1.6+esm4

Affected versions

3.*
3.5.8-6ubuntu3
3.5.17-1ubuntu1
3.5.17-1ubuntu3
3.5.18-1ubuntu1
3.5.18-1ubuntu1.1
3.5.18-1ubuntu1.2
3.5.18-1ubuntu1.3
3.5.18-1ubuntu1.4
3.5.18-1ubuntu1.5
3.5.18-1ubuntu1.6
3.5.18-1ubuntu1.6+esm1
3.5.18-1ubuntu1.6+esm2
3.5.18-1ubuntu1.6+esm3

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
        },
        {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
        },
        {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
        },
        {
            "binary_name": "libgnutls30",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
        },
        {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:Pro:20.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=esm-infra%2Ffocal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.6.13-2ubuntu1.12+esm3

Affected versions

3.*
3.6.9-5ubuntu1
3.6.9-5ubuntu2
3.6.10-5
3.6.11.1-2
3.6.11.1-2ubuntu2
3.6.13-2ubuntu1
3.6.13-2ubuntu1.1
3.6.13-2ubuntu1.2
3.6.13-2ubuntu1.3
3.6.13-2ubuntu1.6
3.6.13-2ubuntu1.7
3.6.13-2ubuntu1.8
3.6.13-2ubuntu1.9
3.6.13-2ubuntu1.10
3.6.13-2ubuntu1.11
3.6.13-2ubuntu1.12
3.6.13-2ubuntu1.12+esm1
3.6.13-2ubuntu1.12+esm2

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
        },
        {
            "binary_name": "guile-gnutls",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
        },
        {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
        },
        {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
        },
        {
            "binary_name": "libgnutls30",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
        },
        {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:Pro:FIPS-preview:22.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=fips-preview%2Fjammy

Affected ranges

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

Affected versions

3.*
3.7.3-4ubuntu1.2+Fips1.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.7.3-4ubuntu1.2+Fips1.1"
        },
        {
            "binary_name": "guile-gnutls",
            "binary_version": "3.7.3-4ubuntu1.2+Fips1.1"
        },
        {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.7.3-4ubuntu1.2+Fips1.1"
        },
        {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.7.3-4ubuntu1.2+Fips1.1"
        },
        {
            "binary_name": "libgnutls30",
            "binary_version": "3.7.3-4ubuntu1.2+Fips1.1"
        },
        {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.7.3-4ubuntu1.2+Fips1.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:Pro:FIPS-updates:22.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=fips-updates%2Fjammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.7.3-4ubuntu1.9+Fips1

Affected versions

3.*
3.7.3-4ubuntu1.2+Fips1.1
3.7.3-4ubuntu1.3+Fips1.1
3.7.3-4ubuntu1.4+Fips1
3.7.3-4ubuntu1.5+Fips1
3.7.3-4ubuntu1.6+Fips1
3.7.3-4ubuntu1.7+Fips1
3.7.3-4ubuntu1.7+Fips1.1
3.7.3-4ubuntu1.8+Fips1.1

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.7.3-4ubuntu1.9+Fips1"
        },
        {
            "binary_name": "guile-gnutls",
            "binary_version": "3.7.3-4ubuntu1.9+Fips1"
        },
        {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.7.3-4ubuntu1.9+Fips1"
        },
        {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.7.3-4ubuntu1.9+Fips1"
        },
        {
            "binary_name": "libgnutls30",
            "binary_version": "3.7.3-4ubuntu1.9+Fips1"
        },
        {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.7.3-4ubuntu1.9+Fips1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"
Ubuntu:Pro:FIPS-updates:24.04:LTS
gnutls28

Package

Name
gnutls28
Purl
pkg:deb/ubuntu/gnutls28?arch=source&distro=fips-updates%2Fnoble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.8.3-1.1ubuntu3.6+Fips1.2

Affected versions

3.*
3.8.3-1.1ubuntu3.1+Fips1
3.8.3-1.1ubuntu3.4+Fips1
3.8.3-1.1ubuntu3.4+Fips1.1
3.8.3-1.1ubuntu3.5+Fips1.1

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "gnutls-bin",
            "binary_version": "3.8.3-1.1ubuntu3.6+Fips1.2"
        },
        {
            "binary_name": "libgnutls-dane0t64",
            "binary_version": "3.8.3-1.1ubuntu3.6+Fips1.2"
        },
        {
            "binary_name": "libgnutls-openssl27t64",
            "binary_version": "3.8.3-1.1ubuntu3.6+Fips1.2"
        },
        {
            "binary_name": "libgnutls30t64",
            "binary_version": "3.8.3-1.1ubuntu3.6+Fips1.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42013.json"