What is CVE-2026-110870?

CVE-2026-110870 is a medium-severity vulnerability in Nodemailer, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-10-14.

How severe is CVE-2026-110870?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Improper input validation in Nodemailer

CVE-2026-110870

Nodemailer from 3.0.0 before 10.0.13 contains an improper input validation vulnerability in its address parser that fails to strip RFC 5322 comments inside angle-bracket addresses. Attackers can supply recipients like a display name with a parenthesized comment in the domain, so illegal characters reach envelope.to and RCPT TO, causing rejected delivery or parser interpretation conflicts that bypass domain allow-lists.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2026-10-14 · last modified 2026-10-15.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

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

Nodemailer

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

github.com/nodemailer/nodemailer/security/advisories/GHSA-g73g-hqqh-jr95 (vendor-advisory)
www.vulncheck.com/advisories/nodemailer-before-10.0.13-improper-input-validatio… (third-party-advisory)

Frequently asked questions

What is CVE-2026-110870?: CVE-2026-110870 is a medium-severity vulnerability in Nodemailer, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-10-14.
How severe is CVE-2026-110870?: Medium severity. CVSS v3 base score is 5.3 out of 10.