5.7
Medium
CVE-2026-12039 Docker Sandboxes (sbx) enforces an HTTP/S-only egress allowlist but does not apply it to DNS resolution: the per-network…
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.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Docker Sandboxes 0.13 | 0.13.0 → < 0.33.0 | 0.33.0 |
References
- docs.docker.com docs.docker.com
- github.com github.com
Timeline
- Published
- Last modified
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