CVE-2026-12039

The record

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.

Affected packages

Related vulnerabilities

• CVE-2026-81871 OpenTelemetry-Go is the Go implementation of OpenTelemetry. CWE-923
• CVE-2026-57028 An Improper Restriction of Communication Channel to Intended Endpoints vulnerability in… CWE-923
• CVE-2026-33803 An Improper Restriction of Communication Channel to Intended Endpoints vulnerability in… CWE-923
• CVE-2026-55655 A flaw was found in OpenSSH. CWE-923
• CVE-2026-12539 Docker Sandboxes (sbx) blocks ICMP egress with an authorizer applied only at… CWE-923
• CVE-2025-36145 IBM watsonx.data 2.2 through 2.3.1 IBM Lakehouse does not properly restrict inbound and… CWE-923
• CVE-2026-22726 Route Services can be leveraged to send app traffic to network destinations outside of an… CWE-923
• CVE-2025-36180 IBM watsonx.data 2.2 through 2.3 IBM Lakehouse does not properly restrict communication… CWE-923