TI-2026-64857 Aliases CVE-2026-100701 GHSA-2mg4-38wg-2h6f

Nodemailer 5.0.0 through 10.0.1 TLS servername Cache Confusion

LOW 26CWE-295Published 2026-09-26 · Updated 2026-09-26

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: High
Attack requirements: Present
Impact type: Spoofing
Confidentiality · integrity · availability: High · Low · None
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-295.

Summary

Nodemailer versions 5.0.0 through 10.0.1 use a process-global DNS cache that is keyed only by the DNS host, while each cache entry also stores the caller-specific TLS servername. When two direct TLS/SMTPS transports (secure: true) resolve the same non-IP host with different tls.servername values, the first transport's servername is returned on the cache hit and overwrites the second transport's explicitly configured value, so Nodemailer sends the wrong SNI value and validates the peer certificate against the wrong identity. In multi-tenant services or SNI-routed SMTP gateways, an attacker who can prime the cache can cause a victim transport to connect to the attacker's TLS virtual host and accept the attacker's certificate even with rejectUnauthorized: true, disclosing the victim's SMTP credentials. Fixed in 10.0.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00114 1st percentileScored 2026-11-07

Fix Partial nodemailer (nodemailer): 10.0.2Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
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	5.0.0 to before 10.0.2	10.0.2	Patch available	CNA

nodemailer Vendornodemailer Affected 5.0.0 to before 10.0.2 Fixed in 10.0.2 Patch available CNA

Remediation

Fix · CNA nodemailer (nodemailer) Fixed in 10.0.2

Fixed in the same release

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

Release · 2026-09-26
nodemailer 10.0.2
2 records Highest priority Priority LOW 2 LOW
Other records, highest priority first
- TI-2026-64858 Nodemailer before 10.0.2 Stack Exhaustion via Nested Recipient ArraysPriority LOW 35
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

2026-10-02 Threatist record created from CVE-2026-100701
2026-10-03 Alias added: GHSA-2mg4-38wg-2h6f
2026-10-27 Affected versions changed · Red Hat

References

Advisory 1

GitHub Security Advisory (GHSA-6vj9-mwq6-2f5v)

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