CVE-2026-55108 in KubeVela
Summary
by MITRE • 08/28/2026
KubeVela is an open source application delivery platform. Prior to 1.9.14, from 1.10.0-alpha.1 until 1.10.9, and from 1.11.0-alpha.1 until 1.11.0-alpha.4, the Terraform remote configuration loader in pkg/controller/utils/capability.go, GetTerraformConfigurationFromRemote, clones a repository supplied through a core.oam.dev/v1beta1 ComponentDefinition and follows repository-controlled variables.tf or main.tf symlinks. A user with permission to create or update ComponentDefinition objects can point variables.tf to /dev/zero through terraform.path, after which os.Stat and os.ReadFile follow the link and read an unbounded stream before ParseTerraformVariables or HCL parsing can reject the content. The read can exhaust memory, OOM-kill the cluster-wide vela-core controller, cause repeated Pod restarts, and pressure node memory when no effective container limit is configured. This issue is fixed in versions 1.9.14, 1.10.9, and 1.11.0-alpha.4.
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Analysis
by VulDB Data Team • 08/28/2026
The vulnerability identified within KubeVela represents a significant resource exhaustion flaw rooted in the improper handling of remote configuration sources during application delivery operations. Specifically, this issue affects the Terraform remote configuration loader located in the pkg/controller/utils/capability.go file, particularly within the GetTerraformConfigurationFromRemote function. The defect manifests across several version ranges including versions prior to 1.9.14, from 1.10.0-alpha.1 through 1.10.9, and from 1.11.0-alpha.1 through 1.11.0-alpha.4. The core of the problem lies in how the system processes symlinks within Terraform configuration files such as variables.tf or main.tf when these are supplied via a core.oam.dev/v1beta1 ComponentDefinition object. When an attacker with permissions to create or update these definitions can manipulate the terraform.path variable, they can redirect it to point towards /dev/zero. This action causes the underlying operating system calls for os.Stat and os.ReadFile to follow the symlink without any size limitation checks before the HCL parsing logic has a chance to validate or reject the content structure.
From a technical perspective, this flaw is classified as an Uncontrolled Resource Consumption vulnerability, aligning with CWE-400 in the Common Weakness Enumeration taxonomy. The mechanism involves the application failing to enforce limits on data ingestion from external sources before processing begins. By pointing the configuration loader at /dev/zero, which provides an infinite stream of null bytes, the system initiates a read operation that continues indefinitely until memory resources are completely depleted. This behavior bypasses the intended validation layers because the parsing functions ParseTerraformVariables or HCL parsers only engage after the file content has already been fully loaded into memory. Consequently, the application does not implement any pre-read size constraints or streaming mechanisms to mitigate the impact of maliciously crafted inputs that exploit this lack of boundary enforcement.
The operational impact of this vulnerability is severe and can lead to a denial-of-service condition for the entire Kubernetes cluster running KubeVela components. As the vela-core controller attempts to process the infinite stream, it rapidly exhausts available memory resources on the node where it resides. This typically results in the Out-Of-Memory killer terminating the controller pod, leading to repeated restart cycles that degrade system stability and availability. In environments where effective container resource limits are not strictly configured via Kubernetes quotas or limit ranges, this attack can pressure overall node memory, potentially affecting other critical workloads running on the same infrastructure. The resulting instability disrupts application delivery workflows and requires manual intervention to restore normal operations by restarting affected pods and addressing the underlying configuration issues.
To mitigate this risk, organizations must upgrade KubeVela to patched versions including 1.9.14, 1.10.9, or 1.11.0-alpha.4 where the code has been updated to handle remote configurations more securely. In addition to upgrading, administrators should enforce strict resource limits on all containers running vela-core components using Kubernetes LimitRange and ResourceQuota objects to prevent any single process from consuming excessive memory even if exploited. Furthermore, input validation strategies should be implemented at the API level to restrict or sanitize paths provided in ComponentDefinition objects, ensuring that symlinks pointing to device files like /dev/zero are rejected before they reach the configuration loader. This defense-in-depth approach aligns with ATT&CK techniques related to Resource Hijacking and Denial of Service via resource exhaustion, emphasizing the need for both software patching and robust infrastructure-level controls to maintain system resilience against such attacks.