Apache Airflow has no certificate validation on SMTP STARTTLS connections

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-49267: 0.18% estimated exploitation activity in the next 30 days; percentile 8.14 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Apache Airflow's EmailOperator and the underlying airflow.utils.email helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used [email] smtpstarttls=True without [email] smtpssl. An attacker positioned between the worker and the configured SMTP server (network MITM — typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker's trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded. This CVE covers the core apache-airflow side of the same root cause already covered for the SMTP provider by CVE-2026-41016 (published 2026-04-27, covering apache-airflow-providers-smtp). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade apache-airflow to 3.2.2 or later to cover the core-side path through airflow.utils.email.…

Published by the source

1 Jun 2026, 09:31 UTC

Last modified by the source

13 Jul 2026, 16:43 UTC

Source last checked

26 Oct 2026, 13:46 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-799x-qp47-8qwq

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-799x-qp47-8qwq

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# Patch Next advisory brief: CVE-2026-49267

Advisory: Apache Airflow has no certificate validation on SMTP STARTTLS connections
IDs: CVE-2026-49267, GHSA-799x-qp47-8qwq
Record: https://patchnext.com/advisories/cve-2026-49267 (revision 2, source checked 26 Oct 2026, 13:46 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: apache-airflow 3.2.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI apache-airflow: affected >= 2.0.0, < 3.2.2; fixed in 3.2.2

## Suggested inspection (read-only)
- `python -m pip show apache-airflow`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on apache-airflow.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-799x-qp47-8qwq (OSV record GHSA-799x-qp47-8qwq lists affected ranges: PyPI apache-airflow >=2.0.0 <3.2.2 (fixed))
- Verified: https://github.com/advisories/GHSA-799x-qp47-8qwq (GitHub-reviewed advisory GHSA-799x-qp47-8qwq lists affected ranges: PyPI apache-airflow >=2.0.0 <3.2.2)

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