Answer in brief
CVE-2026-12039 records a Medium severity (CVSS 5.7) vulnerability in Docker Sandboxes network egress allowlist bypass via unfiltered DNS resolution. The current sources do not mark it as known exploited. The current feed maps Docker/Docker Sandboxes (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Docker/Docker Sandboxes (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Docker/Docker Sandboxesgeneric | >=0.13.0 <0.33.0 | 0.33.0 |
Published upstream
Jun 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 22, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-12039 records a Medium severity (CVSS 5.7) vulnerability in Docker Sandboxes network egress allowlist bypass via unfiltered DNS resolution. The current sources do not mark it as known exploited. The current feed maps Docker/Docker Sandboxes (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Docker/Docker Sandboxes (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Docker/Docker Sandboxesgeneric | >=0.13.0 <0.33.0 | 0.33.0 |
Published upstream
Jun 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 22, 2026
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.
Quoted source text, attributed separately from HOL analysis.