{"id":"CVE-2026-92597","summary":"Nodemailer before 9.1.0 Email Domain Validation Bypass via RFC 5322 Comment","details":"Nodemailer versions \u003e= 6.9.16 and \u003c 9.1.0 mis-parse RFC 5322 comments in email addresses: in lib/addressparser, a comment closed immediately before a non-break character causes the tokenizer to concatenate the atoms surrounding the comment instead of treating the comment as folding whitespace that terminates the domain. A recipient address such as user@good-corp.com(x)evil.com is therefore read by Nodemailer as the single domain good-corp.comevil.com (registrable domain comevil.com, which an attacker can register) and used for both the SMTP envelope (RCPT TO) and the emitted To:/From: headers, while a conformant RFC 5322 parser terminates the domain at the comment and reads good-corp.com. An application that validates the recipient domain with a strict RFC 5322 parser (without inspecting parse defects) or a naive prefix/substring allow-list and then hands the raw address to Nodemailer can be induced to deliver mail to a domain the attacker controls. Fixed in 9.1.0.","aliases":["GHSA-cc9r-2j5m-2m83"],"modified":"2026-09-18T03:48:41.728959141Z","published":"2026-09-16T21:47:01.599Z","database_specific":{"cwe_ids":["CWE-436"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/92xxx/CVE-2026-92597.json","cna_assigner":"VulnCheck"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/92xxx/CVE-2026-92597.json"},{"type":"ADVISORY","url":"https://github.com/nodemailer/nodemailer/security/advisories/GHSA-cc9r-2j5m-2m83"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92597"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/nodemailer-before-9.1.0-email-domain-validation-bypass-via-rfc-5322-comment"},{"type":"FIX","url":"https://github.com/nodemailer/nodemailer/commit/902b63e"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nodemailer/nodemailer","events":[{"introduced":"e70b9c18bd4ba14d500197fa1614ed37f5536446"},{"fixed":"902b63e"}],"database_specific":{"extracted_events":[{"introduced":"6.9.16"},{"fixed":"9.1.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-92597.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N"}]}