curl: CVE-2026-8286: wrong STARTTLS connection reuse

A vulnerability was found in the Curl library that allowed a plain-text connection to reuse an existing SSL-upgraded connection without verifying the SSL configuration. This could lead to a man-in-the-middle attack if an attacker was able to intercept the initial STARTTLS upgrade. The issue was...

GHSA-VCGP-9326-PQCP net-imap vulnerable to STARTTLS stripping via invalid response timing

Summary A man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. Details When using Net::IMAPstarttls to upgrade a plaintext connection to use TLS, a man-in-the-middle attacker can inject a tagged OK response with an easily predictable tag. By sendi...

net-imap vulnerable to STARTTLS stripping via invalid response timing

Summary A man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. Details When using Net::IMAPstarttls to upgrade a plaintext connection to use TLS, a man-in-the-middle attacker can inject a tagged OK response with an easily predictable tag. By sendi...

net-imap vulnerable to STARTTLS stripping via invalid response timing

Summary A man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. Details When using Net::IMAPstarttls to upgrade a plaintext connection to use TLS, a man-in-the-middle attacker can inject a tagged OK response with an easily predictable tag. By sendi...

GHSA-X8MH-94WC-33GV apache-airflow-providers-smtp: No certificate validation on SMTP STARTTLS connections in SMTP provider

Apache 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...

apache-airflow-providers-smtp: No certificate validation on SMTP STARTTLS connections in SMTP provider

Apache 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...

Improper Certificate Validation

Overview apache-airflow-providers-smtp is a Provider for Apache Airflow. Implements apache-airflow-providers-smtp package Affected versions of this package are vulnerable to Improper Certificate Validation in the SmtpHook when establishing a STARTTLS connection. An attacker can intercept SMTP...

CVE-2026-41016

Apache 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...

PYSEC-2026-24

Apache 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...

PYSEC-2026-24

Apache 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...

CVE-2026-41016

The Apache Airflow SMTP provider SmtpHook is vulnerable because it calls smtplib.SMTP.starttls() without an SSL context , leading to a lack of certificate validation during the TLS upgrade. A man-in-the-middle could intercept the connection to capture SMTP credentials during the login() call. Thi...

CVE-2026-41016 Apache Airflow Providers SMTP: No certificate validation on SMTP STARTTLS connections in SMTP provider

Apache 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...

CVE-2026-41016

Apache 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...

CVE-2026-41016 Apache Airflow Providers SMTP: No certificate validation on SMTP STARTTLS connections in SMTP provider

Apache 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...

PT-2026-36084

Name of the Vulnerable Software and Affected Versions apache-airflow-providers-smtp affected versions not specified Description The SmtpHook component in the SMTP provider calls the Python function smtplib.SMTP.starttls without an SSL context. This omission prevents certificate validation during...

CVE-2026-41319 MailKit has STARTTLS Response Injection via unflushed stream buffer that enables SASL mechanism downgrade

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...

CVE-2026-41319

Summary (CVE-2026-41319) MailKit (MimeKit-based) exposes a STARTTLS vulnerability where the internal read buffers of SmtpStream, ImapStream, and Pop3Stream are not flushed when upgrading to TLS with SslStream. This allows pre-TLS attacker-injected data to be treated as post-TLS, enabling a MITM-b...

CVE-2026-41319 MailKit has STARTTLS Response Injection via unflushed stream buffer that enables SASL mechanism downgrade

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...

CVE-2026-41319 MailKit has STARTTLS Response Injection via unflushed stream buffer that enables SASL mechanism downgrade

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...

CVE-2026-41319: Improper Neutralization of Special Elements in Output Used by a Downstream Component

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...