CVE-2026-92543

Publication date 8 October 2026

Last updated 8 October 2026


Ubuntu priority

Description

Docker Engine classifies a registry hostname as insecure using an any-match DNS check. loadInsecureRegistries() injects 127.0.0.0/8 and ::1/128 as insecure CIDRs by default. isCIDRMatch resolves all of the hostname's addresses and returns true if a single address is in the insecure CIDR list. Because the transport re-dials the hostname rather than the CIDR-matching address, a DNS answer set of one loopback IP plus a non-loopback attacker IP disables certificate verification and enables HTTP fallback for the registry connection.

Read the notes from the security team

Status

Package Ubuntu Release Status
docker.io 26.04 LTS resolute
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
docker.io-app 26.04 LTS resolute
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation

Notes


alexmurray

Traditionally the docker.io source package contained both the library and docker application. However, in releases that contain the docker.io-app source package, the docker.io source package contains only the library whilst the docker application itself is contained in the docker.io-app package.


sbeattie

docker packages contain an embedded copy of github:moby/buildkit

Severity score breakdown

CVSS version: CVSS v4.0

Base score 7.6 · High

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N


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