Apache YuniKorn 1.9.0 and earlier fail to validate user and label annotations when a workload is updated. The UPDATE operation bypasses all admission checks, allowing any authorized user to set an arbitrary user annotation or change the application ID. This can let a user run a workload in a queue that they normally are not allowed to use, potentially violating queue quotas and altering user–based quota enforcement. The flaw does not directly expose data or crash the system, but it enables unauthorized resource usage and can lead to resource exhaustion or misreporting of usage.

The vulnerability affects Apache YuniKorn as distributed by the Apache Software Foundation. Versions 1.9.0 and earlier are impacted. Workloads for Kubernetes objects such as deployments, replicasets, statefulsets, daemonsets, jobs, and cronjobs are subject to the update bypass.

The CVSS score of 2.0 reflects a low severity vulnerability. EPSS score of 0.00452 indicates a very low exploitation probability, and the issue is not listed in CISA’s KEV catalog, indicating low reported exploitation risk. The likely attack vector is via remote or local access to the YuniKorn API, where a user who can perform UPDATE requests can leverage the bypass. Because the vulnerability is a missing authorization check, an attacker would need to be authenticated to the YuniKorn service; no privilege escalation beyond that is required.