CVE-2026-12539

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.

Scoring

Severity
MEDIUM
CVSS base score
5.1
CVSS 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
EPSS probability
0.14%
CWE
CWE-923, CWE-665
Published
2026-06-18
Last modified
2026-08-13

Affected products

Weakness type

Related vulnerabilities

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