UBUNTU-CVE-2026-3833

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Source

https://ubuntu.com/security/CVE-2026-3833

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.json

JSON Data

https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2026-3833

Upstream

CVE-2026-3833

Downstream

USN-8284-1

Related

USN-8284-1

Published

2026-04-30T18:16:00Z

Modified

2026-06-02T12:00:06.262191491Z

Severity

6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
7.4 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of nameConstraints labels, specifically for dNSName (DNS) or rfc822Name (email) constraints within excludedSubtrees or permittedSubtrees. A remote attacker can exploit this by crafting a leaf certificate with casing differences in the Subject Alternative Name (SAN), leading to a policy bypass where a certificate that should be rejected is instead accepted. This could result in unauthorized access or information disclosure.

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

0Unknown 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

{
    "binaries": [
        {
            "binary_version": "3.7.3-4ubuntu1.9",
            "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"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.json"

Ubuntu:24.04:LTS

gnutls28

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown 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

{
    "binaries": [
        {
            "binary_version": "3.8.3-1.1ubuntu3.6",
            "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"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.json"

Ubuntu:25.10

gnutls28

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown 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_version": "3.8.9-3ubuntu2.2",
            "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"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.json"

Ubuntu:26.04:LTS

gnutls28

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown 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_version": "3.8.12-2ubuntu1.1",
            "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"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.json"

Ubuntu:Pro:16.04:LTS

gnutls28

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

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

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "3.4.10-4ubuntu1.9+esm2",
            "binary_name": "gnutls-bin"
        },
        {
            "binary_version": "3.4.10-4ubuntu1.9+esm2",
            "binary_name": "guile-gnutls"
        },
        {
            "binary_version": "3.4.10-4ubuntu1.9+esm2",
            "binary_name": "libgnutls-openssl27"
        },
        {
            "binary_version": "3.4.10-4ubuntu1.9+esm2",
            "binary_name": "libgnutls30"
        },
        {
            "binary_version": "3.4.10-4ubuntu1.9+esm2",
            "binary_name": "libgnutlsxx28"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.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

0Unknown introduced version / All previous versions are affected

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

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "3.5.18-1ubuntu1.6+esm2",
            "binary_name": "gnutls-bin"
        },
        {
            "binary_version": "3.5.18-1ubuntu1.6+esm2",
            "binary_name": "libgnutls-dane0"
        },
        {
            "binary_version": "3.5.18-1ubuntu1.6+esm2",
            "binary_name": "libgnutls-openssl27"
        },
        {
            "binary_version": "3.5.18-1ubuntu1.6+esm2",
            "binary_name": "libgnutls30"
        },
        {
            "binary_version": "3.5.18-1ubuntu1.6+esm2",
            "binary_name": "libgnutlsxx28"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.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

0Unknown introduced version / All previous versions are affected

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

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "3.6.13-2ubuntu1.12+esm1",
            "binary_name": "gnutls-bin"
        },
        {
            "binary_version": "3.6.13-2ubuntu1.12+esm1",
            "binary_name": "guile-gnutls"
        },
        {
            "binary_version": "3.6.13-2ubuntu1.12+esm1",
            "binary_name": "libgnutls-dane0"
        },
        {
            "binary_version": "3.6.13-2ubuntu1.12+esm1",
            "binary_name": "libgnutls-openssl27"
        },
        {
            "binary_version": "3.6.13-2ubuntu1.12+esm1",
            "binary_name": "libgnutls30"
        },
        {
            "binary_version": "3.6.13-2ubuntu1.12+esm1",
            "binary_name": "libgnutlsxx28"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.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

0Unknown introduced version / All previous versions are affected

Affected versions

3.*

3.7.3-4ubuntu1.2+Fips1.1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "3.7.3-4ubuntu1.2+Fips1.1",
            "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"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.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

0Unknown 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

{
    "binaries": [
        {
            "binary_version": "3.7.3-4ubuntu1.9+Fips1",
            "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"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.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

0Unknown 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

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

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3833.json"