{"id":"CVE-2026-41016","aliases":["GHSA-x8mh-94wc-33gv","PYSEC-2026-24"],"title":"apache-airflow-providers-smtp: No certificate validation on SMTP STARTTLS connections in SMTP provider","summary":"apache-airflow-providers-smtp: No certificate validation on SMTP STARTTLS connections in SMTP provider","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","vendor":"apache-airflow-providers-smtp","product":"apache-airflow-providers-smtp","ecosystem":"pip","affected":["apache-airflow-providers-smtp >= 2.0.0, < 3.0.0"],"patched":["apache-airflow-providers-smtp 3.0.0"],"published":"2026-04-30","updated":"2026-09-10","sourceUpdated":"2026-09-10T03:51:03.971751299Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-x8mh-94wc-33gv","references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-41016"},{"url":"https://github.com/apache/airflow/pull/65346"},{"url":"https://github.com/apache/airflow"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/apache-airflow-providers-smtp/PYSEC-2026-24.yaml"},{"url":"https://lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4"}],"tags":["osv","pip"],"epss":0.00268,"epssPercentile":0.19142,"ingestedAt":"2026-09-12T03:13:01.739Z","slug":"CVE-2026-41016","body":"## Overview\n\nApache Airflow's SMTP provider `SmtpHook` called Python's `smtplib.SMTP.starttls()` without an SSL context, so no certificate validation was performed on the TLS upgrade. A man-in-the-middle between the Airflow worker and the SMTP server could present a self-signed certificate, complete the STARTTLS upgrade, and capture the SMTP credentials sent during the subsequent `login()` call. Users are advised to upgrade to the `apache-airflow-providers-smtp` version that contains the fix.\n\n## Affected packages\n\n- `apache-airflow-providers-smtp >= 2.0.0, < 3.0.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `apache-airflow-providers-smtp 3.0.0`","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}