UBUNTU-CVE-2026-123596

Source
https://ubuntu.com/security/CVE-2026-123596
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123596.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-123596
Upstream
Published
2026-11-09T00:00:00Z
Modified
2026-11-10T02:50:13Z
Severity
  • 8.8 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the validating recursor's NSEC handler that accepts parent-side ancestor-delegation NSEC records as proof of nonexistence for names below the zone cut. An on-path attacker, rogue parent nameserver, or attacker winning a port and TXID race can deliver one forged NXDOMAIN response built from genuinely signed parent NSEC records, causing authenticated denial of existing child-zone names cached for the negative TTL.

References

Affected packages

Ubuntu:24.04:LTS / rust-hickory-proto

Package

Name
rust-hickory-proto
Purl
pkg:deb/ubuntu/rust-hickory-proto?arch=source&distro=noble

Affected ranges

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

Affected versions

0.*
0.24.0-1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "librust-hickory-proto-dev",
            "binary_version": "0.24.0-1"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123596.json"

Ubuntu:26.10 / rust-hickory-net

Package

Name
rust-hickory-net
Purl
pkg:deb/ubuntu/rust-hickory-net?arch=source&distro=stonking

Affected ranges

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

Affected versions

0.*
0.26.1-1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "librust-hickory-net-dev",
            "binary_version": "0.26.1-1"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123596.json"

Ubuntu:26.10 / rust-hickory-proto

Package

Name
rust-hickory-proto
Purl
pkg:deb/ubuntu/rust-hickory-proto?arch=source&distro=stonking

Affected ranges

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

Affected versions

0.*
0.24.4-6
0.26.1-1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "librust-hickory-proto-dev",
            "binary_version": "0.26.1-1"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123596.json"

Ubuntu:26.04:LTS / rust-hickory-proto

Package

Name
rust-hickory-proto
Purl
pkg:deb/ubuntu/rust-hickory-proto?arch=source&distro=resolute

Affected ranges

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

Affected versions

0.*
0.24.4-4.1
0.24.4-6

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "librust-hickory-proto-dev",
            "binary_version": "0.24.4-6"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123596.json"