CVE-2026-100701

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreHIGH confidence

Score 5.9 from GitHub Security Advisory published 2026-09-26. A secondary CVSS source baseline 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 5.9Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
5.9
EG Score
5.9MEDIUMhigh confidence
EG Risk
27
EG Risk 27/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.1%
EPSS %ILE
1st
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 26, 2026

Last Modified

September 30, 2026

Advisory Details (2)

Auto-updated Sep 26, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

Nodemailer 5.0.0 through 10.0.1 TLS servername Cache Confusion | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nodemailer-5.0.0-through-10.0.1-tls-servername-cache-confusion
github Patch Available🟡 PoC Available

Process-global DNS cache reuses TLS `servername` across transports, enabling cross-tenant SMTP credential disclosure · Advisory · nodemailer/nodemailer · GitHub

https://github.com/nodemailer/nodemailer/security/advisories/GHSA-6vj9-mwq6-2f5v

Vendor Advisories for CVE-2026-100701(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
nodemailer—10.0.2—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 17× in last 7d / 24× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-04 11:06 UTCEG score recompute
  2. 2026-10-04 11:06 UTCGHSA enrichment
  3. 2026-10-03 14:25 UTCEPSS rescore
  4. 2026-10-03 12:31 UTCEG score recompute
  5. 2026-10-03 12:31 UTCGHSA enrichment
  6. 2026-10-02 13:55 UTCEG score recompute
  7. 2026-10-02 13:55 UTCGHSA enrichment
  8. 2026-10-01 19:49 UTCEPSS rescore
  9. 2026-10-01 15:19 UTCGHSA enrichment
  10. 2026-09-30 16:43 UTCEG score recompute
  11. 2026-09-30 16:43 UTCGHSA enrichment
  12. 2026-09-30 15:02 UTCEPSS rescore
  13. 2026-09-29 20:13 UTCGHSA enrichment
  14. 2026-09-28 21:35 UTCEG score recompute
  15. 2026-09-28 21:35 UTCGHSA enrichment
  16. 2026-09-27 23:00 UTCEG score recompute
  17. 2026-09-27 23:00 UTCGHSA enrichment
  18. 2026-09-27 00:23 UTCEG score recompute
  19. 2026-09-27 00:23 UTCGHSA enrichment
  20. 2026-09-26 23:27 UTCEG score recompute
  21. 2026-09-26 23:27 UTCGHSA enrichment
  22. 2026-09-26 14:29 UTCEG score recompute
  23. 2026-09-26 13:34 UTCEG score recompute
  24. 2026-09-26 13:30 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-100701?
CVE-2026-100701 is a medium vulnerability published on September 26, 2026. 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,…
When was CVE-2026-100701 disclosed?
CVE-2026-100701 was first published on September 26, 2026, with the most recent update on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-100701 actively exploited?
CVE-2026-100701 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-100701?
CVE-2026-100701 has a CVSS base score of 5.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-100701?
A fix for CVE-2026-100701 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100701 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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