{"id":"CVE-2026-110869","title":"Nodemailer 3.0.0 before 10.0.13 has a regular expression denial of service in SMTPConnection._actionEHLO, whose four AUTH mechanism detection regexes contain overlapping whitespace sub-patterns that backtrack quadratically","summary":"Nodemailer 3.0.0 before 10.0.13 has a regular expression denial of service in SMTPConnection._actionEHLO, whose four AUTH mechanism detection regexes contain overlapping whitespace sub-patterns that backtrack quadratically. A malicious o…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-1333"],"published":"2026-10-14","updated":"2026-10-14","sourceUpdated":"2026-10-14T23:17:28.673","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-110869","references":[{"url":"https://github.com/nodemailer/nodemailer/security/advisories/GHSA-4ffr-jq9g-5ffx","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/nodemailer-3.0.0-before-10.0.13-redos-via-smtp-auth-mechanism-detection-regexes","label":"disclosure@vulncheck.com"}],"tags":["nvd"],"ingestedAt":"2026-10-15T00:02:07.189Z","slug":"CVE-2026-110869","body":"## Overview\n\nNodemailer 3.0.0 before 10.0.13 has a regular expression denial of service in SMTPConnection._actionEHLO, whose four AUTH mechanism detection regexes contain overlapping whitespace sub-patterns that backtrack quadratically. A malicious or man-in-the-middle SMTP server can reply to EHLO with 250-AUTH, a long whitespace run and a non-matching token, blocking the Node.js event loop for tens of seconds to hours before authentication.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}