CVE-2026-12039

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Source

https://cve.org/CVERecord?id=CVE-2026-12039

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-12039.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-12039

Published

2026-06-18T13:48:14.682Z

Modified

2026-07-08T07:37:03.809242959Z

Severity

5.7 (Medium) CVSS_V4 - 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 CVSS Calculator

Summary

Docker Sandboxes network egress allowlist bypass via unfiltered DNS resolution

Details

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.

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12039.json",
    "cna_assigner": "Docker",
    "cwe_ids": [
        "CWE-923"
    ]
}

References

Affected packages

Git / github.com/docker/sbx-releases

Affected ranges

Type

GIT

Repo

https://github.com/docker/sbx-releases

Events

Introduced

Fixed

e4809b108ff941fbd3dc8ab1edd8755af78ddc07

Database specific

{
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "0.13.0"
        },
        {
            "fixed": "0.33.0"
        }
    ]
}

Affected versions

Other

dev-02f174c

dev-1f51dc0

dev-2631810

dev-438ebd7

dev-78ed158

dev-793e764

dev-8fc2763

dev-921c1c7

dev-a5207e0

dev-ad0ca5e

dev-bad9503

dev-c13a59d

dev-c7702ef

dev-dc73246

dev-e54ee33

dev-ebc3fbe

v0.*

v0.16.0

v0.17.0

v0.18.2

v0.18.3

v0.18.4

v0.18.5

v0.18.6

v0.18.7

v0.19.0

v0.20.0

v0.21.0

v0.23.0

v0.24.1

v0.24.2

v0.25.0

v0.26.1

v0.27.0

v0.28.0

v0.28.1

v0.28.1-rc2

v0.28.2

v0.28.3

v0.29.0

v0.29.0-rc1

v0.30.0

v0.30.0-rc1

v0.30.0-rc2

v0.31.0-rc1

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-12039.json"