containerd CRI server: Host memory exhaustion through Attach goroutine leak

containerd is an open-source container runtime. Versions 1.7.28 and below, 2.0.0-beta.0 through 2.0.6, 2.1.0-beta.0 through 2.1.4, and 2.2.0-beta.0 through 2.2.0-rc.1 contain a bug in the CRI Attach implementation where a user can exhaust memory on the host due to goroutine leaks. This issue is fixed in versions 1.7.29, 2.0.7, 2.1.5 and 2.2.0. To workaround this vulnerability, users can set up an admission controller to control accesses to pods/attach resources.

containerd is an open-source container runtime. Versions 1.7.28 and below, 2.0.0-beta.0 through 2.0.6, 2.1.0-beta.0 through 2.1.4, and 2.2.0-beta.0 through 2.2.0-rc.1 contain a bug in the CRI Attach implementation where a user can exhaust memory on the host due to goroutine leaks. This issue is fixed in versions 1.7.29, 2.0.7, 2.1.5 and 2.2.0. To workaround this vulnerability, users can set up an admission controller to control accesses to pods/attach resources.

containerd is an open-source container runtime. Versions 1.7.28 and below, 2.0.0-beta.0 through 2.0.6, 2.1.0-beta.0 through 2.1.4, and 2.2.0-beta.0 through 2.2.0-rc.1 contain a bug in the CRI Attach implementation where a user can exhaust memory on the host due to goroutine leaks. This issue is fixed in versions 1.7.29, 2.0.7, 2.1.5 and 2.2.0. To workaround this vulnerability, users can set up an admission controller to control accesses to pods/attach resources.

### Impact A bug was found in containerd's CRI Attach implementation where a user can exhaust memory on the host due to goroutine leaks. Repetitive calls of CRI Attach (e.g., [`kubectl attach`](https://kubernetes.io/docs/reference/kubectl/generated/kubectl_attach/)) could increase the memory usage of containerd. ### Patches This bug has been fixed in the following containerd versions: * 2.2.0 * 2.1.5 * 2.0.7 * 1.7.29 Users should update to these versions to resolve the issue. ### Workarounds Set up an admission controller to control accesses to `pods/attach` resources. e.g., [Validating Admission Policy](https://kubernetes.io/docs/reference/access-authn-authz/validating-admission-policy/). ### Credits The containerd project would like to thank @Wheat2018 for responsibly disclosing this issue in accordance with the [containerd security policy](https://github.com/containerd/project/blob/main/SECURITY.md). ### References https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-64329 ### For more information If you have any questions or comments about this advisory: * Open an issue in [containerd](https://github.com/containerd/containerd/issues/new/choose) * Email us at [[email protected]](mailto:[email protected]) To report a security issue in containerd: * [Report a new vulnerability](https://github.com/containerd/containerd/security/advisories/new)

containerd CRI server: Host memory exhaustion through Attach goroutine leak in github.com/containerd/containerd