Database/Container, Kubernetes & orchestration

Nuclio controller: cron trigger headers and body are injected into the CronJob shell command

CVE-2026-52831Container, Kubernetes & orchestrationcurated

Impact

For every cron trigger, the Nuclio controller renders a curl invocation into the args of a Kubernetes CronJob container as /bin/sh -c <command>. The event.headers keys and event.body fields of the trigger spec are not adequately sanitised on the way in, so whoever can write a function's trigger specification chooses what the CronJob actually executes. The command runs in the function's namespace with that CronJob's service account, which is a scope change out of the function author's own boundary and into the cluster. On a shared GPU cluster where tenants supply their own function definitions, this is a lateral move from submit rights into arbitrary in-cluster execution on the scheduler's behalf.

Who can reach it

Requires an authenticated principal with enough privilege to create or modify a Nuclio function's cron trigger spec (the record scores PR:H). Not reachable from an anonymous network position.

What to do

Upgrade to Nuclio 1.16.4 and restart the controller. Because the rendered command is stored in the CronJob object itself, CronJobs the controller created before the upgrade keep the args they were given, so audit and recreate existing cron-trigger CronJobs rather than assuming the controller upgrade cleans them up.

References

https://nvd.nist.gov/vuln/detail/CVE-2026-52831 https://github.com/nuclio/nuclio/security/advisories/GHSA-v5px-423j-pf7p https://github.com/nuclio/nuclio/commit/3356b86a8bfab3f960aa420310ebff765df9dede https://github.com/nuclio/nuclio/releases/tag/1.16.4

This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.