CRLF Injection Affecting mimekit package, versions [,4.15.1)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DOTNET-MIMEKIT-15468175
- published12 Mar 2026
- disclosed5 Mar 2026
- creditKC1zs4
Introduced: 5 Mar 2026
NewCVE-2026-30227 (opens in a new tab)How to fix?
Upgrade MimeKit to version 4.15.1 or higher.
Overview
MimeKit is a C# library which may be used for the creation and parsing of messages using the Multipurpose Internet Mail Extension (MIME), as defined by numerous IETF specifications.
Affected versions of this package are vulnerable to CRLF Injection due to the InternetAddress not rejecting control characters. An attacker can inject SMTP commands by supplying a quoted local-part containing \r\n when constructing a MailboxAddress, causing the SMTP client to emit extra commands via MAIL FROM/RCPT TO.