CVE-2026-12039
Docker Sandboxes network egress allowlist bypass via unfiltered DNS resolution
Description
Docker Sandboxes (sbx) enforces an HTTP/S-only egress allowlist but does not apply it to DNS resolution: the per-network embedded DNS server forwards any queried name to the host resolver whenever the network is internet-connected, without consulting the policy. A workload inside a sandbox, which the threat model treats as untrusted, can therefore encode data into DNS labels for an attacker-controlled domain and exfiltrate it through a DNS covert channel, bypassing the configured allowlist.
No summary for this CVE yet.
Weaknesses
Affected Products
Docker
commercial·US
Exploitability
No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
References
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