Description
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 mechanism downgrade (e.g., forcing PLAIN instead of SCRAM-SHA-256). The internal read buffer in `SmtpStream`, `ImapStream`, and `Pop3Stream` is not flushed when the underlying stream is replaced with `SslStream` during STARTTLS upgrade, causing pre-TLS attacker-injected data to be processed as trusted post-TLS responses. Version 4.16.0 patches the issue.
INFO
Published Date :
2026-04-24T03:07:24.335Z
Last Modified :
2026-04-25T01:46:35.002Z
Source :
GitHub_M
AFFECTED PRODUCTS
The following products are affected by CVE-2026-41319 vulnerability.
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REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-41319.
