Improper Certificate Validation in Apache Airflow - CVE-2026-49267
Published: June 4, 2026
Vulnerability identifier: #VU133378
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-49267
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Apache Foundation
Affected software:
Apache Airflow
Apache Airflow
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose SMTP authentication credentials and email contents.
The vulnerability exists due to improper certificate validation in EmailOperator and airflow.utils.email when establishing SMTP STARTTLS connections. A remote attacker can present a self-signed certificate in a machine-in-the-middle position to disclose SMTP authentication credentials and email contents.
Only deployments with smtp_starttls enabled and smtp_ssl disabled are vulnerable, and the SMTP relay must be reachable across a less-trusted network segment than the worker.
How to mitigate CVE-2026-49267
Install security update from vendor's website.