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Vulnerabilities

Vulnerability · 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.

Published Oct 14, 2026 · catalog updated Oct 15, 2026 · Nodemailer from 3.0.0 before

Check if you run it

No confirmed exploitation is on record for CVE-2026-110871. EPSS is 0.25%. Act only if a listed version of Nodemailer from 3.0.0 before is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Nodemailer from 3.0.0 before).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.25%
Remediation
Advisory link
Affected products
Debian:12 node-nodemailer · Debian:13 node-nodemailer · Debian:14 node-nodemailer · package maven · package npm · vendor nodemailer nodemailer

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:12 node-nodemailer10.0.0+~8.0.1-1, 10.0.10+~8.0.1-1, 10.0.10+~8.0.2-1
  • Debian:13 node-nodemailer10.0.0+~8.0.1-1, 10.0.10+~8.0.1-1, 10.0.10+~8.0.2-1
  • Debian:14 node-nodemailer0 → 10.0.10+~8.0.1-1
  • package mavenversion unspecified
  • package npmversion unspecified
  • vendor nodemailer nodemailerversion unspecified

How to fix CVE-2026-110871

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-110871. EPSS is 0.25%. Act only if a listed version of Nodemailer from 3.0.0 before is installed.

Which versions are affected?

Compare what you have installed with 10.0.0+~8.0.1-1, 10.0.10+~8.0.1-1, 10.0.10+~8.0.2-1, 0 → 10.0.10+~8.0.1-1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-400: Uncontrolled Resource Consumption. EPSS 0.25%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 14, 2026 · NIST NVD

    Detected

    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.

  2. Oct 15, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    node-nodemailer fixed in 10.0.10+~8.0.1-1

  3. Oct 15, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    node-nodemailer fixed in 10.0.10+~8.0.1-1

  4. Oct 15, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    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.

Sources

  • CVE.orgVulnerability recordCVE-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 contin

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-110871

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-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 contin

    nvd.nist.gov
  • OpenSSF OSV / OSV ScannerPackage advisoryDEBIAN-CVE-2026-110871
    osv.dev
  • Snyk Vulnerability DatabasePackage advisorySNYK-JAVA-ORGWEBJARSNPM-20953009

    Inefficient Algorithmic Complexity

    security.snyk.io
  • Snyk Vulnerability DatabasePackage advisorySNYK-JS-NODEMAILER-20953008

    Inefficient Algorithmic Complexity

    security.snyk.io

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.