PT-2026-50676 · Docker · Docker Sandboxes

Published 2026-06-18 · Updated 2026-06-18 · CVE-2026-12539

Mitre

CVSS v4.0

5.7

Medium

Base vector

AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

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.

Fix

Improper Initialization

Weakness Enumeration

CWE-923

CWE-665

Related Identifiers

CVE-2026-12539

Affected Products

Docker Sandboxes

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-12539 · Security Note
• https://github.com/docker/sbx-releases/releases/tag/v0.33.0 · Note
• https://docs.docker.com/ai/sandboxes · Note