Resource exhaustion in Nodemailer
CVE-2026-110871
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 that fold into tens of thousands of continuation lines, blocking the Node.js event loop during DKIM signing.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/nodemailer/nodemailer/security/advisories/GHSA-39m8-27wv-hr27 (vendor-advisory)
- www.vulncheck.com/advisories/nodemailer-3.0.0-before-10.0.10-quadratic-dkim-hea… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-110871?
- CVE-2026-110871 is a medium-severity vulnerability in Nodemailer, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-10-14.
- How severe is CVE-2026-110871?
- Medium severity. CVSS v3 base score is 6.5 out of 10.