Vulnerability · Published Oct 7, 2026 · Assigned by Docker
CVE-2026-92543Docker Engine insecure-registry fallback via malicious DNS responses
High 7.6
In plain English
A high-severity improper certificate validation in Docker Engine from Docker. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 0% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | docker | 29.8.2-r0 | ALPINE-CVE-2026-92543 |
| Debian:12 | docker.io | no fix listed | DEBIAN-CVE-2026-92543 |
| Debian:13 | docker.io | no fix listed | DEBIAN-CVE-2026-92543 |
| Debian:14 | docker.io | no fix listed | DEBIAN-CVE-2026-92543 |
| Ubuntu:26.04:LTS | docker.io | no fix listed | UBUNTU-CVE-2026-92543 |
| Ubuntu:26.10 | docker.io | no fix listed | UBUNTU-CVE-2026-92543 |
| Ubuntu:26.04:LTS | docker.io-app | no fix listed | UBUNTU-CVE-2026-92543 |
| Ubuntu:26.10 | docker.io-app | no fix listed | UBUNTU-CVE-2026-92543 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Docker | Docker Engine | 0 – before 29.8.2 |
| Moby | Moby | 0 – before v2.0.0-beta.25 |
Weakness: CWE-295, CWE-319 · 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