CVE-2026-18874 in Advanced Cluster Management for Kubernetes
Summary
by MITRE • 08/19/2026
A flaw was found in volsync-addon-controller. This vulnerability allows an attacker to inject malicious YAML (Yet Another Markup Language) code into the OpenShift Lifecycle Manager (OLM) Subscription resource. This is due to improper escaping of annotation values when they are rendered into YAML. Successful exploitation could lead to unauthorized modification or control over OLM Subscription configurations, potentially impacting software management within the cluster. This issue primarily affects systems where the 'volsync-addon-deploy-type: olm' annotation is explicitly enabled.
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Analysis
by VulDB Data Team • 08/19/2026
The vulnerability identified in volsync-addon-controller represents a critical security flaw rooted in improper input validation and sanitization mechanisms during the rendering of YAML configurations for OpenShift Lifecycle Manager subscriptions. Specifically, when the controller processes annotations associated with subscription resources, it fails to adequately escape special characters or control sequences within annotation values before injecting them into the resulting YAML structure. This technical deficiency allows an attacker who possesses write access to modify these specific annotations to inject arbitrary malicious code directly into the configuration files that govern software deployment and lifecycle management operations within the cluster. The root cause lies in the lack of strict schema validation and context-aware escaping when transforming user-supplied annotation data into executable or interpretable YAML structures, a common pitfall in applications that dynamically generate configuration files from untrusted inputs without rigorous sanitization protocols.
From an operational perspective, this vulnerability poses a severe risk to the integrity and availability of software management processes within OpenShift clusters where the volsync-addon-deploy-type is set to olm. By successfully exploiting this flaw, an attacker can manipulate OLM Subscription configurations, potentially altering deployment targets, injecting malicious container images, or disrupting the update cycles managed by the lifecycle manager. This unauthorized modification capability effectively grants the attacker a degree of control over how software components are deployed and maintained across the cluster infrastructure. Such manipulation could lead to the installation of compromised workloads, denial of service through configuration corruption, or further lateral movement if the injected code facilitates privilege escalation within the container runtime environment. The impact is particularly acute in environments where automated deployment pipelines rely on these subscription resources for continuous delivery and updates.
This vulnerability aligns with CWE-94, commonly known as Improper Control of Generation of Code (Code Injection), specifically involving YAML parsing issues that allow unintended code execution or configuration manipulation. In the context of the MITRE ATT&CK framework, this flaw facilitates techniques associated with Initial Access via compromised credentials or supply chain compromise if an attacker can influence the annotation values through existing legitimate accounts, and it supports Persistence mechanisms by ensuring malicious configurations are applied during subsequent reconciliation cycles managed by OLM. The exploitation vector primarily targets systems where explicit configuration flags enable the vulnerable code path, highlighting that while not all installations are affected, those with specific addon deployment types enabled remain at significant risk.
To mitigate this vulnerability, immediate remediation should focus on upgrading to a patched version of volsync-addon-controller that implements robust input validation and strict escaping mechanisms for all annotation values before they are rendered into YAML structures. Administrators must also enforce least-privilege access controls to ensure that only authorized service accounts or users with specific permissions can modify subscription annotations, thereby reducing the attack surface available to potential adversaries. Additionally, implementing admission controllers such as OPA Gatekeeper or Kyverno can provide an additional layer of defense by validating annotation formats and rejecting any inputs containing suspicious patterns indicative of injection attempts. Regular auditing of configuration changes and monitoring for anomalous modifications to OLM resources are also recommended practices to detect exploitation attempts early in the attack lifecycle.