Unity Linux 20.1060e / 20.1070e Security Update: fetchmail (UTSA-2026-017438)

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-017438 advisory. Fetchmail before 6.4.22 fails to enforce STARTTLS session encryption in some circumstances, such as a certain situation with IMAP and PREAUTH. Tenable has extracted...

DEBIAN-CVE-2026-42246

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

CVE-2026-42246

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

UBUNTU-CVE-2026-42246

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

CVE-2026-42246

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

CVE-2026-42246

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

CVE-2026-42246 net-imap vulnerable to STARTTLS stripping via invalid response timing

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

CVE-2026-42246 net-imap vulnerable to STARTTLS stripping via invalid response timing

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

CVE-2026-42246

Net::IMAP (Ruby) versions before 0.3.10, 0.4.24, 0.5.14, and 0.6.4 are affected by a STARTTLS stripping issue. A man-in-the-middle attacker can cause Net::IMAP#starttls to report a successful TLS upgrade without actually enabling TLS, leaving the socket unencrypted. The vulnerability is mitigated...

EUVD-2026-28924

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

CVE-2026-42246

Net::IMAP implements Internet Message Access Protocol IMAP client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10,...

Net::IMAP 安全漏洞

Net::IMAP is a Ruby client API for the IMAP message access protocol, developed by Ruby Open Source. Versions of Net::IMAP prior to 0.3.10, 0.4.24, 0.5.14, and 0.6.4 contained security vulnerabilities. These vulnerabilities stemmed from the possibility for man-in-the-middle attackers to cause...

Ruby net-imap < 0.3.10 / 0.4.x < 0.4.24 / 0.5.x < 0.5.14 / 0.6.x < 0.6.4 vulnerability

The version of the net-imap Ruby library installed on the remote host is prior to 0.3.10, 0.4.x prior to 0.4.24, 0.5.x prior to 0.5.14, or 0.6.x prior to 0.6.4. It is, therefore, affected by a man-in-the-middle vulnerability. A flaw in the Net::IMAPstarttls function allows a man-in-the-middle...

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...

PT-2026-37183

Name of the Vulnerable Software and Affected Versions Net::IMAP versions prior to 0.3.10 Net::IMAP versions prior to 0.4.24 Net::IMAP versions prior to 0.5.14 Net::IMAP versions prior to 0.6.4 Description A man-in-the-middle attacker can cause the starttls function to return successfully without...

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...

Astra Linux – Vulnerability in Ruby2.5, JRuby

A issue was discovered in Ruby between versions 2.6.7, 2.7.x up to 2.7.3, and 3.x up to 3.0.1. The Net::IMAP library does not raise an exception when the StartTLS command fails with an unknown response. This may allow man-in-the-middle attackers to bypass TLS protections by leveraging the network...

Astra Linux – Vulnerability in curl

When curl version 7.20.0 or later connects to an IMAP or POP3 server to retrieve data using STARTTLS to upgrade to TLS security, the server can send multiple responses at once, which are cached by curl. In this case, curl upgrades to TLS, but it does not discard the cached responses. Instead, it...

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...