CVE-2026-110871Nodemailer 3.0.0 before 10.0.10 Quadratic DKIM Header Unfolding Denial of Service

Description

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.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• GitHub Security Advisory (GHSA-39m8-27wv-hr27) vendor-advisory
• VulnCheck Advisory: Nodemailer 3.0.0 before 10.0.10 Quadratic DKIM Header Unfolding Denial of Service third-party-advisory