CVE-2026-110869

high

Description

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 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.

References

https://www.vulncheck.com/advisories/nodemailer-3.0.0-before-10.0.13-redos-via-smtp-auth-mechanism-detection-regexes

https://github.com/nodemailer/nodemailer/security/advisories/GHSA-4ffr-jq9g-5ffx

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-101752

Details

Source: Mitre, NVD

Published: 2026-10-14

Updated: 2026-10-14

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: High