CVE-2026-12039
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.
- CVSS 4.0
- 5.7
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - EPSS
- 0.1% chance of exploitation in the next 30 days; higher than 0% of CVEs (scores of 2026-10-25)
- CWE
- CWE-923
- Published
- Modified
- Record from
- the NVD, synced