Vulnerability-Lookup

FKIE_CVE-2026-30227

Vulnerability from fkie_nvd - Published: 2026-03-06 21:16 - Updated: 2026-03-12 15:34

Severity ?

5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

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.

References

	URL	Tags
	security-advisories@github.com	https://github.com/jstedfast/MimeKit/security/advisories/GHSA-g7hc-96xr-gvvx	Exploit, Mitigation, Vendor Advisory

Impacted products

	Vendor	Product	Version
	jstedfast	mimekit	*

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:jstedfast:mimekit:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "23724BF5-DA1C-4F23-BB68-30B4A6C6231B",
              "versionEndExcluding": "4.15.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    },
    {
      "lang": "es",
      "value": "MimeKit es una librer\u00eda C# que puede ser utilizada para la creaci\u00f3n y el an\u00e1lisis de mensajes utilizando la Extensi\u00f3n de Correo de Internet Multiprop\u00f3sito (MIME), tal como lo definen numerosas especificaciones del IETF. Antes de la versi\u00f3n 4.15.1, una vulnerabilidad de inyecci\u00f3n CRLF en MimeKit permite a un atacante incrustar \\r\\n en la parte local de la direcci\u00f3n del sobre SMTP (cuando la parte local es una cadena entre comillas). Esto no cumple con la RFC 5321 y puede resultar en inyecci\u00f3n de comandos SMTP (por ejemplo, inyectando comandos RCPT a / DATA / RSET adicionales) y/o inyecci\u00f3n de encabezados de correo, dependiendo de c\u00f3mo la aplicaci\u00f3n utilice MailKit/MimeKit para construir y enviar mensajes. El problema se vuelve explotable cuando el atacante puede influir en un valor de MailboxAddress (MAIL FROM / RCPT TO) que luego se serializa a una sesi\u00f3n SMTP. La RFC 5321 define expl\u00edcitamente la gram\u00e1tica de la parte local del buz\u00f3n SMTP y no permite CR (13) o LF (10) dentro de Quoted-string (los rangos qtextSMTP y quoted-pairSMTP excluyen caracteres de control). Los comandos SMTP son terminados por , haciendo que la inyecci\u00f3n CRLF en los argumentos de los comandos sea particularmente peligrosa. Este problema ha sido parcheado en la versi\u00f3n 4.15.1."
    }
  ],
  "id": "CVE-2026-30227",
  "lastModified": "2026-03-12T15:34:59.480",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "LOW",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-03-06T21:16:16.607",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://github.com/jstedfast/MimeKit/security/advisories/GHSA-g7hc-96xr-gvvx"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-93"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

CVE-2026-30227 (GCVE-0-2026-30227)

Vulnerability from cvelistv5 – Published: 2026-03-06 21:07 – Updated: 2026-03-09 20:54

Title

MimeKit: CRLF Injection in Quoted Local-Part Enables SMTP Command Injection and Email Forgery

Summary

Severity ?

6.9 (Medium)


                        
                          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

CWE

CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')

Assigner

GitHub_M

References

URL

Tags

https://github.com/jstedfast/MimeKit/security/adv…

x_refsource_CONFIRM

Impacted products

	Vendor	Product	Version
	jstedfast	MimeKit	Affected: < 4.15.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
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        "metrics": [
          {
            "other": {
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                "id": "CVE-2026-30227",
                "options": [
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                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-09T20:46:30.556894Z",
                "version": "2.0.3"
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    "cna": {
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      "metrics": [
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Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2026-30227

CVE-2026-30227 (GCVE-0-2026-30227)

Tags

Sightings

Nomenclature