CVE-2026-84173: Eclipse Ankaios Information Disclosure Flaw

CVE-2026-84173 Overview

CVE-2026-84173 is an authorization flaw in Eclipse Ankaios, a container workload orchestrator for automotive and embedded systems. Versions v0.5.1 through v1.0.1 contain a defect in the agent-side Control Interface authorizer. The component incorrectly evaluates multi-segment allow rules whose first path segment is a wildcard. An authenticated workload restricted by such a rule can submit a CompleteStateRequest or UpdateStateRequest with an empty field mask and be granted full cluster-state access. The flaw is classified under CWE-863: Incorrect Authorization.

Critical Impact
A restricted workload can read the entire cluster state or overwrite state outside its authorized subtree, enabling unauthorized disclosure or modification of other workloads and cluster configuration.

Affected Products

Eclipse Ankaios v0.5.1 through v1.0.1
Ankaios agent Control Interface authorizer component
Workload deployments relying on multi-segment allow rules beginning with *

Discovery Timeline

2026-09-07 - CVE-2026-84173 published to NVD
2026-09-08 - Last updated in NVD database

Technical Details for CVE-2026-84173

Vulnerability Analysis

Eclipse Ankaios enforces per-workload access to cluster state through Control Interface allow-rule filter masks. Each rule specifies a dotted path such as desiredState.workloads.some_workload that scopes a workload's read and write authority. The authorizer must reject requests whose field mask falls outside the rule's scope.

In affected versions, the authorizer mishandles multi-segment rules where the first segment is *, for example *.workloads.some_workload. When such a scoped workload submits a CompleteStateRequest or UpdateStateRequest with an empty field mask, the authorizer treats the empty mask as matching the scoped rule. Only a rule consisting solely of * is intended to authorize an empty mask, which represents unrestricted full-state access.

The result is a broken access control condition. A workload intended to touch only its own subtree gains equivalent authority to a fully privileged rule. This allows disclosure of secrets or configuration belonging to other workloads and modification of arbitrary cluster state.

Root Cause

The defect is a logic error in path-matching between the requested field mask and the configured allow rule. The wildcard-prefixed multi-segment rule is treated as satisfied by an empty request mask, even though the empty mask semantically requests the entire state tree. The fix, delivered in pull request #790, enforces that only a rule of exactly * authorizes an empty mask.

Attack Vector

Exploitation requires an authenticated workload already permitted to communicate with the local Ankaios agent through the Control Interface. The attacker submits a CompleteStateRequest with no field mask to read the complete cluster state, or an UpdateStateRequest with no field mask to replace state elsewhere. No user interaction is required, and the attack executes locally against the agent socket. See the GitHub Security Advisory GHSA-rp6v-x3q5-cp2g for the reference request patterns.

Detection Methods for CVE-2026-84173

Indicators of Compromise

Control Interface audit entries showing CompleteStateRequest messages from workloads whose configured allow rule begins with a wildcard segment.
UpdateStateRequest messages carrying an empty field mask from workloads that should only touch a narrow subtree.
Unexpected changes in desiredState.workloads.* entries originating from workloads that do not own those subtrees.

Detection Strategies

Inventory all Ankaios control-interface allow rules and flag any filter mask whose first segment is * followed by additional segments.
Correlate agent logs with workload identity to identify state reads or writes outside a workload's declared scope.
Alert on Control Interface requests where the field mask is empty and the source workload is not intended to have full-state access.

Monitoring Recommendations

Forward Ankaios agent logs to a centralized analytics platform and retain request-level audit data for post-incident review.
Track cluster state diffs and attribute each modification to the requesting workload identity.
Baseline expected Control Interface traffic per workload and alert on deviations in request type or scope.

How to Mitigate CVE-2026-84173

Immediate Actions Required

Upgrade all Ankaios agents and servers to v1.0.2 or later.
Audit every deployed workload manifest for allow rules beginning with *. and rewrite them with explicit path prefixes.
Restrict which workloads may communicate with the Control Interface until patched versions are rolled out.

Patch Information

Eclipse Ankaios v1.0.2 contains the fix delivered through pull request #790. The patch ensures that only a filter mask consisting solely of * authorizes an empty request mask, and that multi-segment wildcard rules are evaluated against the actual requested scope. Refer to the GitLab Vulnerability Report #853 for the coordinated disclosure record.

Workarounds

Replace rules such as *.workloads.some_workload with explicit paths, for example desiredState.workloads.some_workload.
Reserve the single-character * rule strictly for workloads that legitimately require full-state access.
Remove or tighten any allow rule whose semantics cannot be expressed without a leading wildcard segment.

bash

# Example: replace wildcard-prefixed rule with an explicit path
# Vulnerable configuration
# controlInterfaceAccess:
#   allowRules:
#     - type: StateRule
#       operation: ReadWrite
#       filterMask:
#         - "*.workloads.some_workload"

# Fixed configuration
controlInterfaceAccess:
  allowRules:
    - type: StateRule
      operation: ReadWrite
      filterMask:
        - "desiredState.workloads.some_workload"