Vulnerability · Published Jun 18, 2026 · Assigned by Docker
CVE-2026-12539Docker Sandboxes ICMP egress restriction bypass after daemon restart
Medium 5.1
In plain English
A medium-severity security flaw in Docker Sandboxes from Docker. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Docker | Docker Sandboxes | 0.14.0 – before 0.33.0 |
Weakness: CWE-923, CWE-665 · 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