Docker Sandboxes (sbx) blocks ICMP egress with an authorizer applied only at network-creation time, and does not re-apply it to networks rebuilt from disk when the Docker daemon restarts, so a restart-surviving sandbox forwards ICMP to arbitrary hosts. A workload inside a sandbox, which the threat model treats as untrusted, can therefore defeat the documented ICMP egress block to perform network reconnaissance and exfiltrate data over an ICMP covert channel, regardless of the configured allowlist.
History

Thu, 18 Jun 2026 16:45:00 +0000

Type Values Removed Values Added
Description Docker Sandboxes (sbx) blocks ICMP egress with an authorizer applied only at network-creation time, and does not re-apply it to networks rebuilt from disk when the Docker daemon restarts, so a restart-surviving sandbox forwards ICMP to arbitrary hosts. A workload inside a sandbox, which the threat model treats as untrusted, can therefore defeat the documented ICMP egress block to perform network reconnaissance and exfiltrate data over an ICMP covert channel, regardless of the configured allowlist.
Title Docker Sandboxes ICMP egress restriction bypass after daemon restart
Weaknesses CWE-665
CWE-923
References
Metrics cvssV4_0

{'score': 5.7, 'vector': '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'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Docker

Published:

Updated: 2026-06-18T14:56:02.329Z

Reserved: 2026-06-17T15:31:11.749Z

Link: CVE-2026-12539

cve-icon Vulnrichment

Updated: 2026-06-18T14:55:59.351Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-18T18:15:02Z