{"url":"http://public2.vulnerablecode.io/api/vulnerabilities/66416?format=json","vulnerability_id":"VCID-sph5-vrkh-uugr","summary":"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 <CRLF>, making CRLF injection in command arguments particularly dangerous. This issue has been patched in version 4.15.1.","aliases":[{"alias":"CVE-2026-30227"},{"alias":"GHSA-g7hc-96xr-gvvx"}],"fixed_packages":[{"url":"http://public2.vulnerablecode.io/api/packages/40316?format=json","purl":"pkg:nuget/MimeKit@4.15.1","is_vulnerable":false,"affected_by_vulnerabilities":[],"resource_url":"http://public2.vulnerablecode.io/packages/pkg:nuget/MimeKit@4.15.1"}],"affected_packages":[{"url":"http://public2.vulnerablecode.io/api/packages/40315?format=json","purl":"pkg:nuget/MimeKit@4.15.0","is_vulnerable":true,"affected_by_vulnerabilities":[{"vulnerability":"VCID-sph5-vrkh-uugr"}],"resource_url":"http://public2.vulnerablecode.io/packages/pkg:nuget/MimeKit@4.15.0"}],"references":[{"reference_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-30227","reference_id":"CVE-2026-30227","reference_type":"","scores":[],"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-30227"},{"reference_url":"https://github.com/advisories/GHSA-g7hc-96xr-gvvx","reference_id":"GHSA-g7hc-96xr-gvvx","reference_type":"","scores":[{"value":"MODERATE","scoring_system":"cvssv3.1_qr","scoring_elements":""}],"url":"https://github.com/advisories/GHSA-g7hc-96xr-gvvx"},{"reference_url":"https://github.com/jstedfast/MimeKit/security/advisories/GHSA-g7hc-96xr-gvvx","reference_id":"GHSA-g7hc-96xr-gvvx","reference_type":"","scores":[{"value":"MODERATE","scoring_system":"cvssv3.1_qr","scoring_elements":""},{"value":"6.9","scoring_system":"cvssv4","scoring_elements":"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"},{"value":"Track","scoring_system":"ssvc","scoring_elements":"SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2026-03-09T20:46:30Z/"}],"url":"https://github.com/jstedfast/MimeKit/security/advisories/GHSA-g7hc-96xr-gvvx"}],"weaknesses":[{"cwe_id":93,"name":"Improper Neutralization of CRLF Sequences ('CRLF Injection')","description":"The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs."}],"exploits":[],"severity_range_score":"4.0 - 6.9","exploitability":null,"weighted_severity":null,"risk_score":null,"resource_url":"http://public2.vulnerablecode.io/vulnerabilities/VCID-sph5-vrkh-uugr"}