CVE-2026-86836: eclipse foundation eclipse ankaios Incorrect Default Permissions

Vulnerability summary

CVE-2026-86836 is a high (CVSS 8.4) Incorrect Default Permissions vulnerability in eclipse foundation eclipse ankaios. EPSS estimates a 0.11% chance of exploitation in the next 30 days, higher than 1.3% of scored vulnerabilities.

Timeline

1. 14-09-2026
   PublishedVulnerability first disclosed.
2. 15-09-2026
   Last modifiedVulnerability information updated.

Description

In Eclipse Ankaios versions 0.1.0 through 1.0.2, the agent creates workload files and Control Interface named pipes (FIFOs) under a predictable path derived from the agent name and a hash of the workload's runtime configuration. If a directory or FIFO already exists at that path when the agent (re)starts, the agent reuses it based only on an existence and/or file-type check, without validating its owner or permissions. A local, unprivileged user with write access to the same base directory (by default under `$TMPDIR/ankaios`, e.g. shared `/tmp`) can pre-create this path hierarchy, including the two Control Interface FIFOs, before the agent starts. The agent then treats the attacker-owned FIFOs as the legitimate Control Interface for the targeted workload. The attacker can complete the Control Interface handshake and issue requests using that workload's configured `controlInterfaceAccess` permissions, allowing impersonation of the workload and, depending on its configured permissions, unauthorized reading and/or modification of the cluster's desired state.

• CWE-276Incorrect Default PermissionsDuring installation, installed file permissions are set to allow anyone to modify those files.
• CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionThe product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
• CWE-379Creation of Temporary File in Directory with Insecure PermissionsThe product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.