Bug 2547596 (CVE-2026-92543) - CVE-2026-92543 github.com/moby/moby: Docker Engine: Certificate verification bypass via flawed registry DNS check
Summary: CVE-2026-92543 github.com/moby/moby: Docker Engine: Certificate verification ...
Keywords:
Status: NEW
Alias: CVE-2026-92543
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-07 17:11 UTC by OSIDB Bzimport
Modified: 2026-10-07 21:38 UTC (History)
33 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-10-07 17:11:57 UTC 
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.
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