TI-2026-74562 Aliases CVE-2026-110872

Denial of service in Nodemailer SMTP reply parsing

HIGH 69CWE-400Published 2026-10-14 · Updated 2026-10-15

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: High
Attack requirements: Present
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 3 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-400.

Summary

Nodemailer from 3.0.0 before 10.0.10 has a denial of service flaw in its SMTP client reply parser. The parser consumes resources without limit (CWE-400), so its work grows quadratically with the size of server replies. A malicious SMTP server or an on-path attacker can stream continuation lines without a completion line before authentication, blocking the Node.js event loop and exhausting memory.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00355 29th percentileScored 2026-11-07

Fix Partial nodemailer (nodemailer): 10.0.10Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
nodemailer	nodemailer	3.0.0 to before 10.0.10	10.0.10	Patch available	CNA

nodemailer Vendornodemailer Affected 3.0.0 to before 10.0.10 Fixed in 10.0.10 Patch available CNA

Remediation

Upgrade Nodemailer to version 10.0.10 or later. Red Hat lists Red Hat Developer Hub 1, Red Hat Enterprise Linux 10 and Self-service automation portal 2 as affected without a fix and with no plan available.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Fix · CNA nodemailer (nodemailer) Fixed in 10.0.10

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-10-14
nodemailer 10.0.10
2 records Highest priority Priority HIGH 1 HIGH, 1 MEDIUM
Other records, highest priority first
- TI-2026-74561 Quadratic header unfolding in Nodemailer enables denial of servicePriority MEDIUM 64
Show all 2 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Developer Hub 1	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Self-service automation portal 2	Affected	No fix yet: Fix deferred

Not affected: 1 product

Red Hat Hardened Images

Timeline

2026-10-15 Threatist record created from CVE-2026-110872
2026-10-15 CISA SSVC decision points changed
2026-10-15 Priority changed: MEDIUM → HIGH
2026-10-16 Affected versions changed · Red Hat
2026-10-16 CVSS score added · Red Hat
2026-10-27 Affected versions changed · Red Hat

References

Advisory 1

GitHub Security Advisory (GHSA-4g23-2xm8-66gc)

TI-2026-74559 ReDoS in Nodemailer SMTP AUTH mechanism detection regexes CVSS 4.0HIGH 8.7
TI-2026-64856 nodemailer before 10.0.6 Denial of Service via addressparser CVSS 4.0HIGH 8.7
TI-2026-62452 Nodemailer before 9.1.0 Denial of Service via addressparser CVSS 4.0HIGH 8.7
TI-2026-61683 Nodemailer 9.1.0 through 10.0.4 Denial of Service via Quadratic Address Parsing CVSS 4.0HIGH 8.7
TI-2025-13566 Nodemailer: nodemailer: denial of service via crafted email address header CVSS 3.1HIGH 7.5
TI-2026-74560 Nodemailer address parser passes illegal characters to SMTP envelope CVSS 4.0MEDIUM 6.9

See all 27 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences