{"id":"CVE-2026-110871","title":"Nodemailer from 3.0.0 before 10.0.10 contains a denial of service vulnerability in MessageParser.parseHeaders that allows users to exhaust CPU through quadratic header unfolding","summary":"Nodemailer from 3.0.0 before 10.0.10 contains a denial of service vulnerability in MessageParser.parseHeaders that allows users to exhaust CPU through quadratic header unfolding. Attackers can supply large recipient lists or long headers…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-400","CWE-1322","CWE-407"],"published":"2026-10-14","updated":"2026-10-14","sourceUpdated":"2026-10-14T23:17:28.953","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-110871","references":[{"url":"https://github.com/nodemailer/nodemailer/security/advisories/GHSA-39m8-27wv-hr27","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/nodemailer-3.0.0-before-10.0.10-quadratic-dkim-header-unfolding-denial-of-service","label":"disclosure@vulncheck.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-110871.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-110871"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2552965"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-110871"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-110871"},{"url":"https://github.com/nodemailer/nodemailer/commit/28a5909cec27646cb001dc7e97a8f5d26c973078"},{"url":"https://github.com/nodemailer/nodemailer/releases/tag/v10.0.10"},{"url":"https://github.com/advisories/GHSA-39m8-27wv-hr27"}],"tags":["nvd","cve.org","csaf","vex","red-hat","exploit-available","ghsa","npm"],"ingestedAt":"2026-10-15T00:02:07.189Z","vendor":"nodemailer","product":"nodemailer","affected":["nodemailer >= 3.0.0 < 10.0.10"],"epss":0.00381,"epssPercentile":0.31879,"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-20T02:27:46.223988Z"},"aliases":["GHSA-39m8-27wv-hr27"],"ecosystem":"npm","patched":["nodemailer 10.0.10"],"slug":"CVE-2026-110871","body":"## Overview\n\nNodemailer from 3.0.0 before 10.0.10 contains a denial of service vulnerability in MessageParser.parseHeaders that allows users to exhaust CPU through quadratic header unfolding. Attackers can supply large recipient lists or long headers that fold into tens of thousands of continuation lines, blocking the Node.js event loop during DKIM signing.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Developer Hub, Red Hat Enterprise Linux 10, Self-service automation portal 2 · no fix planned: Red Hat Developer Hub, Red Hat Enterprise Linux 10, Self-service automation portal 2 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-110871.json)\n\n## Package advisory (CVE-2026-110871)\n\nAffected packages:\n\n- `nodemailer >= 3.0.0, <= 10.0.9`\n\nPatched in:\n\n- `nodemailer 10.0.10`\n\nSource: https://github.com/advisories/GHSA-39m8-27wv-hr27","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":225319,"id":"CVE-2026-110871","ts":1792464719369,"field":"exploit_available","old":"false","new":"true"}]}