{"cve":"CVE-2026-100699","nvd":{"published":"2026-09-26T14:16:54.867","modified":"2026-09-30T16:32:17.940","status":"Awaiting Analysis","description":"Nodemailer is a Node.js email-sending library. In versions >= 9.1.0 and < 10.0.9, the address parser (src/addressparser) mishandles addresses whose local-part is a quoted string and that are followed by RFC 5322 comments, allowing trailing comment-separated domain atoms to be retained in the normalized address. For example, the input \"user\"@example.com(x)evil.com is parsed to the address value 'user@example.com evil.com', which contains additional attacker-controlled domain text separated by a literal space. This parsed value is used without further strict recipient validation when the message envelope is built (envelope.to in src/mime-node), so a malformed/ambiguous recipient address can be accepted and placed in the SMTP envelope. Whether this results in delivery to an unintended recipient on real SMTP servers has not been confirmed. The issue is a variant of the RFC 5322 comment parsing problem addressed in GHSA-cc9r-2j5m-2m83, affecting the separate quoted-local-part code path. Version 10.0.9 contains a fix.","cvss_v4":{"vector":"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","score":6.9},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3},"cwes":["CWE-20"],"references":["https://github.com/nodemailer/nodemailer/security/advisories/GHSA-g57g-f23g-4646","https://www.vulncheck.com/advisories/nodemailer-before-10.0.9-malformed-envelope-recipient-via-rfc-5322-comment","https://github.com/nodemailer/nodemailer/security/advisories/GHSA-g57g-f23g-4646"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-100699","score":0.00233,"percentile":0.14099,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-g57g-f23g-4646","url":"https://osv.dev/vulnerability/GHSA-g57g-f23g-4646","summary":"Nodemailer: Quoted local-part can produce malformed envelope recipient through RFC 5322 comment parsing","modified":"2026-09-30T00:00:03.851424904Z","packages":[{"ecosystem":"npm","name":"nodemailer","purl":"pkg:npm/nodemailer","ranges":[">=9.1.0 <10.0.9"],"fixed":["10.0.9"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}