GHSA-36xw-fx78-c5r4 · Severity: medium · Ecosystem: go — containerd-shim API Exposed to Host Network Containers
containerd is an industry-standard container runtime and is available as a daemon for Linux and Windows. In containerd before versions 1.3.9 and 1.4.3, the containerd-shim API is improperly exposed to host network containers. Access controls for the shim’s API socket verified that the connecting process had an effective UID of 0, but did not otherwise restrict access to the abstract Unix domain socket. This would allow malicious containers running in the same network namespace as the shim, with an effective UID of 0 but otherwise reduced privileges, to cause new processes to be run with elevated privileges. This vulnerability has been fixed in containerd 1.3.9 and 1.4.3. Users should update to these versions as soon as they are released. It should be noted that containers started with an old version of containerd-shim should be stopped and restarted, as running containers will continue to be vulnerable even after an upgrade. If you are not providing the ability for untrusted users to start containers in the same network namespace as the shim (typically the "host" network namespace, for example with docker run --net=host or hostNetwork: true in a Kubernetes pod) and run with an effective UID of 0, you are not vulnerable to this issue. If you are running containers with a vulnerable configuration, you can deny access to all abstract sockets with AppArmor by adding a line similar to deny unix addr=@**, to your policy. It is best practice to run containers with a reduced set of privileges, with a non-zero UID, and with isolated namespaces. The containerd maintainers strongly advise against sharing namespaces with the host. Reducing the set of isolation mechanisms used for a container necessarily increases that container's privilege, regardless of what container runtime is used for running that container.
Conclusion & alert: CVE-2020-15257 is rated Moderate Risk (46.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.24%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 12.38% | 3.24% | -9.14% |
| 2 | 2026-06-06 | 13.30% | 12.38% | -0.93% |
| 3 | 2026-05-28 | — | 13.30% | — |
Full EPSS history (28 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.2 | 3.1 | MEDIUM |
|
2.0 | 2.7 | [email protected] |
| 5.2 | 3.1 | MEDIUM |
|
2.0 | 2.7 | [email protected] |
| 3.6 | 2.0 | LOW |
|
3.9 | 4.9 | [email protected] |
GHSA-36xw-fx78-c5r4 · Severity: medium · Ecosystem: go — containerd-shim API Exposed to Host Network Containers
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
medium | CVE-2020-15257: 3 source package rows (containerd, docker, k3s); 31 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 21, open 10. | https://security.alpinelinux.org/vuln/CVE-2020-15257 |
debian
|
not yet assigned | CVE-2020-15257 not yet assigned priority: Debian including 2 source packages (containerd, docker.io), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. | https://security-tracker.debian.org/tracker/CVE-2020-15257 |
gentoo
|
high | CVE-2020-15257: 1 GLSA(s) (202105-33), 1 atom(s) (app-emulation/containerd); latest impact high. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-15257 |
redhat
|
high | — | https://access.redhat.com/security/cve/CVE-2020-15257 |
suse
|
high | — | https://www.suse.com/security/cve/CVE-2020-15257/ |
ubuntu
|
medium | CVE-2020-15257 medium priority: Ubuntu including 1 source packages (containerd), 6 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): released 4, DNE 1, pending 1. | https://ubuntu.com/security/CVE-2020-15257 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| linuxfoundation | containerd | < 1.3.9 | cpe:2.3:a:linuxfoundation:containerd:*:*:*:*:*:*:*:* |
| linuxfoundation | containerd | >= 1.4.0, < 1.4.3 | cpe:2.3:a:linuxfoundation:containerd:*:*:*:*:*:*:*:* |
| fedoraproject | fedora | 33 | cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* |
| debian | debian_linux | 10.0 | cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://github.com/containerd/containerd/commit/4a4bb851f5da563ff6e68a83dc837c7699c469ad | Patch Third Party Advisory |
| https://github.com/containerd/containerd/releases/tag/v1.4.3 | Third Party Advisory |
| https://github.com/containerd/containerd/security/advisories/GHSA-36xw-fx78-c5r4 | Mitigation Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LNKXLOLZWO5FMAPX63ZL7JNKTNNT5NQD/ | |
| https://security.gentoo.org/glsa/202105-33 | Third Party Advisory |
| https://www.debian.org/security/2021/dsa-4865 | Third Party Advisory |