Nodemailer from 3.0.0 before 10.0.10 contains a quadratic complexity denial of service vulnerability in the SMTP client reply parser in SMTPConnection._onData and isPartialResponse. A malicious SMTP server or on-path attacker can stream continuation lines without a completion line before authentication, blocking the Node.js event loop and exhausting memory.

Attack Vector Network

Attack Complexity High

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00291.

Exploitation poc

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
nodemailer nodemailer unaffected
Version Status Constraints
3.0.0 affected < 10.0.10
10.0.10 unaffected —

No data.

No data.

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No data.

Project Subscriptions

Vendors Products
Nodemailer Subscribe
Nodemailer Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/nodemailer/nodemailer/security/advisories/GHSA-4g23-2xm8-66gc cve-icon cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-110872 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-110872 cve-icon
https://www.vulncheck.com/advisories/nodemailer-3.0.0-before-10.0.10-denial-of-service-via-smtp-reply-parsing cve-icon cve-icon cve-icon
History

Thu, 15 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 15 Oct 2026 13:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1322
References
Metrics threat_severity

None

 threat_severity

Moderate

Wed, 14 Oct 2026 23:00:00 +0000

Type Values Removed Values Added
Description Nodemailer from 3.0.0 before 10.0.10 contains a quadratic complexity denial of service vulnerability in the SMTP client reply parser in SMTPConnection._onData and isPartialResponse. A malicious SMTP server or on-path attacker can stream continuation lines without a completion line before authentication, blocking the Node.js event loop and exhausting memory.
Title Nodemailer 3.0.0 before 10.0.10 Denial of Service via SMTP Reply Parsing
First Time appeared Nodemailer
Nodemailer nodemailer
Weaknesses CWE-400
CPEs cpe:2.3:a:nodemailer:nodemailer:*:*:*:*:*:*:*:*
Vendors & Products Nodemailer
Nodemailer nodemailer
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-15T13:30:56.785Z

Reserved: 2026-10-14T22:21:21.397Z

Link: CVE-2026-110872

cve-icon Vulnrichment

Updated: 2026-10-15T13:30:24.865Z

cve-icon NVD

Status : Received

Published: 2026-10-14T23:17:29.097

Modified: 2026-10-15T14:17:21.940

Link: CVE-2026-110872

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-14T22:53:00Z

Links: CVE-2026-110872 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-15T12:00:18Z

Weaknesses