Credential disclosure via unverified SMTP STARTTLS
Published Jun 1, 2026 · Updated Jun 1, 2026
Improper certificate validation in Apache Airflow 2.0.0 through 3.2.1 allows man-in-the-middle attackers to read SMTP credentials and message contents. The airflow.utils.email send_mime_email path called SMTP.starttls() without an SSL context, causing the TLS handshake to accept attacker-controlled certificates before SMTP authentication. Exploitation requires smtp_starttls=True, smtp_ssl=False, email dispatch, and a network position between an Airflow worker and its SMTP relay; exposure is limited to transmitted credentials and message contents.
Summary
What happened
Improper certificate validation in Apache Airflow 2.0.0 through 3.2.1 allows man-in-the-middle attackers to read SMTP credentials and message contents. The airflow.utils.email send_mime_email path called SMTP.starttls() without an SSL context, causing the TLS handshake to accept attacker-controlled certificates before SMTP authentication. Exploitation requires smtp_starttls=True, smtp_ssl=False, email dispatch, and a network position between an Airflow worker and its SMTP relay; exposure is limited to transmitted credentials and message contents.
The record
- CVE
- CVE-2026-49267
- Published
- Jun 1, 2026
- Updated
- Jun 1, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache Airflow
- Classifications
- CWE-295, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 1, 2026CVE publishedPublication date reported by the CVE source.
- Jun 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.0.0 <3.2.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo