SecuriTricks - CVE-2026-12039

Description

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.

Product(s) Impacted

Vendor	Product	Versions
Docker	Docker	*

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-923

Improper Restriction of Communication Channel to Intended Endpoints

The product establishes a communication channel to (or from) an endpoint for privileged or protected operations, but it does not properly ensure that it is communicating with the correct endpoint.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	docker	docker	/	/	/	/	/	/	/	/

References

https://docs.docker.com/ai/sandboxes/

https://github.com/docker/sbx-releases/releases/tag/v0.33.0

CVSS Score

5.7 / 10

CVSS Data - 4.0

Attack Vector: LOCAL
Attack Complexity: LOW
Attack Requirements: PRESENT
Privileges Required: LOW
User Interaction: NONE
Scope:
Confidentiality Impact: HIGH
Integrity Impact: NONE
Availability Impact: NONE
Exploit Maturity: NOT_DEFINED

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

View Vector String

Timeline

Published: June 18, 2026, 2:17 p.m.
Last Modified: June 18, 2026, 4:16 p.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

CVE-2026-12039