{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5c79dcc7c7c6c238aec40747ecf7481393a3d04e"
            }
          ],
          "repo": "https://github.com/jstedfast/mimekit",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-g7hc-96xr-gvvx"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-93"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/30xxx/CVE-2026-30227.json"
  },
  "details": "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. Prior to version 4.15.1, a CRLF injection vulnerability in MimeKit allows an attacker to embed \\r\\n into the SMTP envelope address local-part (when the local-part is a quoted-string). This is non-compliant with RFC 5321 and can result in SMTP command injection (e.g., injecting additional RCPT TO / DATA / RSET commands) and/or mail header injection, depending on how the application uses MailKit/MimeKit to construct and send messages. The issue becomes exploitable when the attacker can influence a MailboxAddress (MAIL FROM / RCPT TO) value that is later serialized to an SMTP session. RFC 5321 explicitly defines the SMTP mailbox local-part grammar and does not permit CR (13) or LF (10) inside Quoted-string (qtextSMTP and quoted-pairSMTP ranges exclude control characters). SMTP commands are terminated by \u003cCRLF\u003e, making CRLF injection in command arguments particularly dangerous. This issue has been patched in version 4.15.1.",
  "id": "CVE-2026-30227",
  "modified": "2026-03-14T13:47:28.011645222Z",
  "published": "2026-03-06T21:07:49.691Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/30xxx/CVE-2026-30227.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/jstedfast/MimeKit/security/advisories/GHSA-g7hc-96xr-gvvx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-30227"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "MimeKit: CRLF Injection in Quoted Local-Part Enables SMTP Command Injection and Email Forgery"
}