RHACS EUVD-2026-51508

Requires an authenticated principal (user or service account) holding Kubernetes RBAC permission to create Deployments in a cluster monitored by RHACS 4 (PR:L). The concrete trigger is setting the Deployment's openshift.io/encoded-deployment-config label to the literal string "null", which causes ACS to substitute empty UID, name and labels and namespace "default". Limiting factors: the attacker cannot exploit this without Deployment-create rights, so purely external unauthenticated attackers are excluded; it affects the RHACS 4.x product line specifically; and success degrades detection/telemetry rather than directly compromising the host or exfiltrating data. No user interaction is required (UI:N).

The supplied CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N, base 8.5) indicates a low-privileged, network-reachable, low-complexity attack with no user interaction and a scope change into Central, consistent with the description since the attacker needs only Deployment-create RBAC and interacts through the Kubernetes API. The dominant impact is integrity (I:H): the trustworthiness of ACS's security telemetry is undermined rather than the confidentiality of data - the C:L rating is generous, as this is primarily an integrity/detection-evasion flaw, so treat confidentiality impact as marginal. No EPSS score, KEV entry, POC, or SSVC decision data was provided, so exploitation probability cannot be quantified from the input, and absence of these signals is not evidence of low risk. Real-world priority is moderate-to-high for organizations relying on ACS as a compliance and enforcement control, because successful use silently blinds the very tool meant to detect malicious workloads; however, it presupposes an attacker already holding Deployment-create rights in the cluster, which bounds the population of who can abuse it.

An attacker who has obtained a namespace service account or user credential with permission to create Deployments submits a Deployment manifest with the label openshift.io/encoded-deployment-config set to "null". ACS parses the workload with empty identity metadata and a "default" namespace, so the malicious container passes deploy-time policy checks and its violations are never correctly recorded in Central. No public POC is identified at time of analysis.