A bug in containerd's CRI ExecSync implementation allows exec probes and lifecycle hooks with background child processes to keep containerd's stdio-drain goroutines indefinitely blocked. Because the I/O drain phase lacks a default timeout or context cancellation handling, repeated ExecSync invocations (like probes) that include long-lived background processes against a container can cause containerd to leak goroutines and host memory. Over time, this resource exhaustion can cause the containerd daemon to be terminated by the OOM killer, rendering containerd unavailable until it is restarted. This issue affects containerd on Linux systems running with the CRI plugin enabled. Users not using containerd's CRI implementation or not running containers on Linux are not affected.
This bug has been fixed in containerd 2.3.5, 2.2.8, 2.0.12, and 1.7.35. Users should update to these versions to resolve the issue.
Ensure exec probes and lifecycle hooks do not launch long-lived background child processes.
The containerd project would like to thank XlabAI Team of Tencent Xuanwu Lab ([email protected]), including Guannan Wang, Zhanpeng Liu, Jiashuo Liang, and Guancheng Li, and @IamwhatIamSY who independently discovered and responsibly disclosed this issue in accordance with the containerd security policy.
If there are any questions or comments about this advisory:
To report a security issue in containerd:
| Software | Affected versions |
|---|---|
github.com/containerd/containerd/v2
|
< 2.0.12 |
github.com/containerd/containerd
|
< 1.7.35 |
github.com/containerd/containerd/v2
|
>= 2.2.0, < 2.2.8 |
github.com/containerd/containerd/v2
|
>= 2.3.0, < 2.3.5 |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
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Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
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