Docker Engine insecure-registry fallback via malicious DNS responses
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.
CVE-2026-92543
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-92543
Docker Engine
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Moby
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "Docker",
"product": "Docker Engine",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "29.8.2",
"versionType": "semver"
}
],
"defaultStatus": "unaffected"
},
{
"vendor": "Moby",
"product": "Moby",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "v2.0.0-beta.25",
"versionType": "semver"
}
],
"packageName": "github.com/moby/moby/v2",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-92543
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #12278 · Revision 1
- Added to Heist Feed
- Publisher date