CVE-2026-85201 in Ankaios
Summary
by MITRE • 09/07/2026
In Eclipse Ankaios versions 0.1.0 through 1.0.1, the agent does not limit the length declared by a workload in a length-delimited protobuf message received through the Control Interface FIFO. A workload granted Control Interface access can specify an excessive message length, causing an unbounded memory allocation that may abort the Ankaios agent process. This results in loss of orchestration services for workloads managed by the affected agent.
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Analysis
by VulDB Data Team • 09/07/2026
The vulnerability identified in Eclipse Ankaios versions 0.1.0 through 1.0.1 represents a critical flaw within the Control Interface FIFO mechanism, specifically affecting how the agent processes length-delimited Protocol Buffers messages from workload agents. The core technical deficiency lies in the absence of input validation regarding the declared message length field inherent to protobuf serialization formats. When a workload is granted access to the Control Interface, it gains the ability to send commands and data structures to the central Ankaios agent. In this specific implementation, the agent reads the length prefix from the incoming stream but fails to verify whether this value falls within acceptable bounds before proceeding with memory allocation. This oversight allows an attacker or a compromised workload to specify an excessively large message size in the header of the protobuf payload.
Upon receiving such a maliciously crafted packet, the Ankaios agent attempts to allocate heap memory corresponding directly to the declared length without performing any sanity checks against system limits or predefined maximums. Because there is no upper bound enforcement on this allocation request, the process triggers an unbounded memory allocation event. Depending on the available system resources and the magnitude of the specified length, this action rapidly exhausts the agent's memory pool. The operating system typically responds to such extreme resource consumption by terminating the offending process via signals like SIGKILL or through out-of-memory killer mechanisms, resulting in a complete crash of the Ankaios agent service. This behavior classifies as an uncontrolled resource consumption vulnerability, aligning with CWE-400 (Uncontrolled Resource Consumption) and more specifically CWE-789 (Memory Allocation with Excessive Size Value).
The operational impact of this flaw is severe due to the central role played by the Ankaios agent in container orchestration. The agent acts as the primary controller for managing workloads, handling scheduling decisions, health checks, and state synchronization across the cluster. When the agent process aborts unexpectedly, it causes an immediate loss of orchestration services. This disruption can lead to a cascade effect where dependent workloads lose their management context, potentially resulting in service outages, data inconsistency during active transactions, or inability to deploy new resources until the agent is manually restarted and re-initialized. The availability of critical infrastructure components is thus directly compromised by this single point of failure introduced through improper input validation.
From a threat modeling perspective, this vulnerability facilitates Denial of Service attacks against orchestration platforms. It maps closely to ATT&CK technique T1499 (Endpoint Denial of Service), specifically under the sub-technique for resource exhaustion via application layer protocols. An adversary with access to any workload that has been granted Control Interface permissions can exploit this flaw to destabilize the entire cluster environment without needing elevated privileges beyond those assigned to standard workloads. This highlights a significant risk in environments where least privilege principles are not strictly enforced regarding interface access, as even low-privilege accounts can cause high-severity disruptions.
Mitigation strategies must focus on both immediate patching and architectural hardening. The primary remediation is to upgrade the Eclipse Ankaios installation to version 1.0.2 or later, where this validation logic has been corrected to enforce strict bounds checking on protobuf message lengths before memory allocation occurs. In addition to upgrading, organizations should review their access control policies for the Control Interface FIFO. It is advisable to restrict write permissions to only those workloads that absolutely require direct communication with the agent, adhering to the principle of least privilege. Furthermore, implementing network-level rate limiting and payload size restrictions at the container runtime or service mesh layer can provide an additional defense-in-depth measure, ensuring that even if a specific application vulnerability exists, it cannot easily exhaust system resources through oversized payloads. Regular auditing of interface permissions and monitoring for abnormal memory usage patterns in agent processes will also aid in early detection of such exploitation attempts.