CVE-2026-12539
Docker Sandboxes ICMP egress restriction bypass after daemon restart
Description
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.
INFO
Published Date :
June 18, 2026, 1:51 p.m.
Last Modified :
June 18, 2026, 1:54 p.m.
Remotely Exploit :
No
Source :
Docker
Affected Products
The following products are affected by CVE-2026-12539
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 686469e6-3ff6-451b-ab8b-cf5b9e89401e |
Solution
- Reconfigure Docker daemon to reapply network authorizers.
- Implement persistent network policy enforcement.
- Monitor for unauthorized ICMP egress.
- Test network egress rules after restarts.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-12539 vulnerability anywhere in the article.