CVE-2026-35406: Aardvark-dns is an authoritative dns server for A/AAAA container records

Routine

MEDIUM 6.2UPGRADE

CVE-2026-35406 is a medium-severity flaw (CVSS 6.2) affecting aardvark-dns. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Aardvark-dns is an authoritative dns server for A/AAAA container records. From 1.16.0 to 1.17.0, a truncated TCP DNS query followed by a connection reset causes aardvark-dns to enter an unrecoverable infinite error loop at 100% CPU. This vulnerability is fixed in 1.17.1.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.2 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 68%)
CISA exploited list	No
Weakness	CWE-400, CWE-835
Published	2026-04-07
Last modified	2026-07-24

Publisher (CNA): GitHub, Inc. · Vendor: containers

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-07 22:16 UTCPublished CVE record published
2026-07-24 21:10 UTCUpdated Record last modified

containers aardvark-dns UPGRADE

Affected: >= 1.16.0 and < 1.17.1

Fixed in: 1.17.1

Safe to downgrade to: a release before 1.16.0

1. Check installed version

apt-cache policy aardvark-dns || rpm -q aardvark-dns || aardvark-dns --version

2. UPGRADE to 1.17.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade aardvark-dns

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade aardvark-dns

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.16.0 (Debian / Ubuntu)

apt-cache madison aardvark-dns sudo apt install aardvark-dns=<VERSION_BEFORE_1.16.0> sudo apt-mark hold aardvark-dns

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list aardvark-dns sudo dnf downgrade aardvark-dns-<VERSION_BEFORE_1.16.0> sudo dnf versionlock add aardvark-dns

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Advisories and coverage

Official advisories

AlmaLinux Errata: [ALSA-2026:36318] Moderate: aardvark-dns security update 2026-07-08

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-35406?

aardvark-dns: upgrade to 1.17.1. Exact commands for each OS are on this page.

Is CVE-2026-35406 being exploited?

CVE-2026-35406 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-35406 affect?

CVE-2026-35406 affects aardvark-dns. Severity is medium (CVSS 6.2). Aardvark-dns is an authoritative dns server for A/AAAA container records. From 1.16.0 to 1.17.0, a truncated TCP DNS query followed by a connection reset causes aardvark-dns to enter an unrecoverable infinite error loop at 100% CPU. This vu

How urgent is CVE-2026-35406?

Priority 30/100. No elevated risk signals yet.

References

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