UBUNTU-CVE-2026-82720

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Source

https://ubuntu.com/security/CVE-2026-82720

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82720.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-82720

Upstream

CVE-2026-82720

Published

2026-09-17T00:00:00Z

Modified

2026-09-17T13:30:09Z

Severity

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

Summary

[none]

Details

NLnet Labs Unbound 1.12.0 up to and including 1.26.0 has a use-after-free vulnerability when compiled for DNS-over-HTTPs support with '--with-libnghttp2'. During failure code paths (i.e., RPZ drop query, jostle due to heavy traffic), a dropped DoH stream brings down the whole DoH session and does not account properly for other DoH streams in the same session. This leads to use-after-free in those code paths. If the prerequisites are satisfied (possible RPZ drop or heavy client traffic), a malicious actor can trigger the vulnerability with a single DoH connection and the appropriate traffic. Impact is limited as the reads are not user controlled and the use-after-free leads to early returns. However, a hardened allocator can catch the use-after-free and controllably terminate the process resulting to denial of service.

References

Affected packages

Ubuntu:22.04:LTS

unbound

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.13.1-1ubuntu1

1.13.1-1ubuntu3

1.13.1-1ubuntu5

1.13.1-1ubuntu5.1

1.13.1-1ubuntu5.2

1.13.1-1ubuntu5.3

1.13.1-1ubuntu5.4

1.13.1-1ubuntu5.5

1.13.1-1ubuntu5.7

1.13.1-1ubuntu5.8

1.13.1-1ubuntu5.10

1.13.1-1ubuntu5.11

1.13.1-1ubuntu5.12

1.13.1-1ubuntu5.13

1.13.1-1ubuntu5.14

1.13.1-1ubuntu5.15

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libunbound8",
            "binary_version": "1.13.1-1ubuntu5.15"
        },
        {
            "binary_name": "python3-unbound",
            "binary_version": "1.13.1-1ubuntu5.15"
        },
        {
            "binary_name": "unbound",
            "binary_version": "1.13.1-1ubuntu5.15"
        },
        {
            "binary_name": "unbound-anchor",
            "binary_version": "1.13.1-1ubuntu5.15"
        },
        {
            "binary_name": "unbound-host",
            "binary_version": "1.13.1-1ubuntu5.15"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82720.json"

Ubuntu:24.04:LTS

unbound

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.17.1-2

1.18.0-2ubuntu1

1.18.0-2ubuntu2

1.19.1-1ubuntu1

1.19.2-1ubuntu1

1.19.2-1ubuntu3

1.19.2-1ubuntu3.1

1.19.2-1ubuntu3.2

1.19.2-1ubuntu3.3

1.19.2-1ubuntu3.4

1.19.2-1ubuntu3.5

1.19.2-1ubuntu3.6

1.19.2-1ubuntu3.7

1.19.2-1ubuntu3.8

1.19.2-1ubuntu3.9

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libunbound8",
            "binary_version": "1.19.2-1ubuntu3.9"
        },
        {
            "binary_name": "python3-unbound",
            "binary_version": "1.19.2-1ubuntu3.9"
        },
        {
            "binary_name": "unbound",
            "binary_version": "1.19.2-1ubuntu3.9"
        },
        {
            "binary_name": "unbound-anchor",
            "binary_version": "1.19.2-1ubuntu3.9"
        },
        {
            "binary_name": "unbound-host",
            "binary_version": "1.19.2-1ubuntu3.9"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82720.json"

Ubuntu:26.04:LTS

unbound

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.22.0-2ubuntu2

1.22.0-2ubuntu4

1.24.2-1ubuntu1

1.24.2-1ubuntu2

1.24.2-1ubuntu2.1

1.24.2-1ubuntu2.2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libunbound8",
            "binary_version": "1.24.2-1ubuntu2.2"
        },
        {
            "binary_name": "python3-unbound",
            "binary_version": "1.24.2-1ubuntu2.2"
        },
        {
            "binary_name": "unbound",
            "binary_version": "1.24.2-1ubuntu2.2"
        },
        {
            "binary_name": "unbound-anchor",
            "binary_version": "1.24.2-1ubuntu2.2"
        },
        {
            "binary_name": "unbound-host",
            "binary_version": "1.24.2-1ubuntu2.2"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82720.json"

Ubuntu:Pro:14.04:LTS

unbound

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.4.20-1

1.4.21-1

1.4.21-1ubuntu1

1.4.21-1ubuntu2

1.4.22-1ubuntu1

1.4.22-1ubuntu2

1.4.22-1ubuntu3

1.4.22-1ubuntu4

1.4.22-1ubuntu4.14.04.1

1.4.22-1ubuntu4.14.04.2

1.4.22-1ubuntu4.14.04.3

1.4.22-1ubuntu4.14.04.3+esm1

1.4.22-1ubuntu4.14.04.3+esm2

1.4.22-1ubuntu4.14.04.3+esm3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libunbound2",
            "binary_version": "1.4.22-1ubuntu4.14.04.3+esm3"
        },
        {
            "binary_name": "python-unbound",
            "binary_version": "1.4.22-1ubuntu4.14.04.3+esm3"
        },
        {
            "binary_name": "unbound",
            "binary_version": "1.4.22-1ubuntu4.14.04.3+esm3"
        },
        {
            "binary_name": "unbound-anchor",
            "binary_version": "1.4.22-1ubuntu4.14.04.3+esm3"
        },
        {
            "binary_name": "unbound-host",
            "binary_version": "1.4.22-1ubuntu4.14.04.3+esm3"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82720.json"

Ubuntu:Pro:16.04:LTS

unbound

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.4.22-1ubuntu6

1.5.7-1ubuntu1

1.5.7-1ubuntu2

1.5.8-1ubuntu1

1.5.8-1ubuntu1.1

1.5.8-1ubuntu1.1+esm1

1.5.8-1ubuntu1.1+esm2

1.5.8-1ubuntu1.1+esm3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libunbound2",
            "binary_version": "1.5.8-1ubuntu1.1+esm3"
        },
        {
            "binary_name": "python-unbound",
            "binary_version": "1.5.8-1ubuntu1.1+esm3"
        },
        {
            "binary_name": "unbound",
            "binary_version": "1.5.8-1ubuntu1.1+esm3"
        },
        {
            "binary_name": "unbound-anchor",
            "binary_version": "1.5.8-1ubuntu1.1+esm3"
        },
        {
            "binary_name": "unbound-host",
            "binary_version": "1.5.8-1ubuntu1.1+esm3"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82720.json"

Ubuntu:Pro:18.04:LTS

unbound

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.6.5-1

1.6.7-1

1.6.7-1build1

1.6.7-1ubuntu1

1.6.7-1ubuntu2

1.6.7-1ubuntu2.1

1.6.7-1ubuntu2.2

1.6.7-1ubuntu2.3

1.6.7-1ubuntu2.4

1.6.7-1ubuntu2.5

1.6.7-1ubuntu2.6

1.6.7-1ubuntu2.6+esm2

1.6.7-1ubuntu2.6+esm3

1.6.7-1ubuntu2.6+esm4

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libunbound2",
            "binary_version": "1.6.7-1ubuntu2.6+esm4"
        },
        {
            "binary_name": "python-unbound",
            "binary_version": "1.6.7-1ubuntu2.6+esm4"
        },
        {
            "binary_name": "python3-unbound",
            "binary_version": "1.6.7-1ubuntu2.6+esm4"
        },
        {
            "binary_name": "unbound",
            "binary_version": "1.6.7-1ubuntu2.6+esm4"
        },
        {
            "binary_name": "unbound-anchor",
            "binary_version": "1.6.7-1ubuntu2.6+esm4"
        },
        {
            "binary_name": "unbound-host",
            "binary_version": "1.6.7-1ubuntu2.6+esm4"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82720.json"

Ubuntu:Pro:20.04:LTS

unbound

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.9.0-2ubuntu1

1.9.0-2ubuntu2

1.9.4-2

1.9.4-2ubuntu1

1.9.4-2ubuntu1.1

1.9.4-2ubuntu1.2

1.9.4-2ubuntu1.3

1.9.4-2ubuntu1.4

1.9.4-2ubuntu1.5

1.9.4-2ubuntu1.6

1.9.4-2ubuntu1.8

1.9.4-2ubuntu1.9

1.9.4-2ubuntu1.11

1.9.4-2ubuntu1.11+esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libunbound8",
            "binary_version": "1.9.4-2ubuntu1.11+esm1"
        },
        {
            "binary_name": "python-unbound",
            "binary_version": "1.9.4-2ubuntu1.11+esm1"
        },
        {
            "binary_name": "python3-unbound",
            "binary_version": "1.9.4-2ubuntu1.11+esm1"
        },
        {
            "binary_name": "unbound",
            "binary_version": "1.9.4-2ubuntu1.11+esm1"
        },
        {
            "binary_name": "unbound-anchor",
            "binary_version": "1.9.4-2ubuntu1.11+esm1"
        },
        {
            "binary_name": "unbound-host",
            "binary_version": "1.9.4-2ubuntu1.11+esm1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82720.json"