Nodemailer before 9.1.0 fails to apply UTS-46 normalization when encoding international domain names, causing the domain resolver to compute a different Punycode A-label than standards-compliant parsers. Attackers can craft recipient addresses with invisible characters or compatibility mappings that pass domain allow-list checks but are delivered to attacker-controlled domains via SMTP.
CVE-2026-92598
MEDIUMPre-NVD 6.56.5—Trending — 4 sources updated this weekElevated
EchelonGraph scoreHIGH confidence
Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-17. a secondary CVSS source baseline 6.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: Elevated riskExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.5
- EG Score
- 6.5(high)
- EG Risk
- 45(Track)EG Risk 45/100SSVC: Track
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 computedSeverity65% × 45%Exploitation40% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 19%
- KEV
- Not listed
Published
September 16, 2026
Last Modified
September 17, 2026
Advisory Details (4)
Auto-updated Sep 16, 2026🔬 Proof of concept available. Patch available. Sources: github, github_commit.
generic
Nodemailer before 9.1.0 IDN/Punycode Domain Allow-list Bypass | Advisories | VulnCheck
https://www.vulncheck.com/advisories/nodemailer-before-9.1.0-idn-punycode-domain-allow-list-bypassgithub_commit Patch Available
commit b212ac4 (nodemailer/nodemailer)
Patch available: nodemailer/nodemailer v9.1.0 (contains commit b212ac4)
https://github.com/nodemailer/nodemailer/commit/b212ac4github_commit Patch Available
commit 259c32d (nodemailer/nodemailer)
Patch available: nodemailer/nodemailer v9.1.0 (contains commit 259c32d)
https://github.com/nodemailer/nodemailer/commit/259c32dgithub Patch Available🟡 PoC Available
IDN/Punycode domain allow-list bypass leads to email delivery to an attacker-controlled domain · Advisory · nodemailer/nodemailer · GitHub
Affected: 9.1.0
https://github.com/nodemailer/nodemailer/security/advisories/GHSA-wmmp-3585-3rmpVendor Advisories for CVE-2026-92598(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)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| nodemailer | — | 9.1.0 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 11× 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.
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 14:53 UTCEG score recompute
- 2026-09-18 14:53 UTCGHSA enrichment
- 2026-09-17 19:32 UTCEPSS rescore
- 2026-09-17 15:23 UTCEG score recompute
- 2026-09-17 15:23 UTCGHSA enrichment
- 2026-09-17 14:49 UTCEG score recompute
- 2026-09-17 14:49 UTCGHSA enrichment
- 2026-09-16 22:26 UTCEG score recompute
- 2026-09-16 21:54 UTCEG score recompute
- 2026-09-16 21:54 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-92598?
CVE-2026-92598 is a medium vulnerability published on September 16, 2026. Nodemailer before 9.1.0 fails to apply UTS-46 normalization when encoding international domain names, causing the domain resolver to compute a different Punycode A-label than standards-compliant parsers. Attackers can craft recipient addresses with invisible characters or compatibility mappings…
When was CVE-2026-92598 disclosed?
CVE-2026-92598 was first published in the National Vulnerability Database on September 16, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-92598 actively exploited?
CVE-2026-92598 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.4% of all scored CVEs.
What is the CVSS score of CVE-2026-92598?
CVE-2026-92598 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-92598?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-92598, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-92598
Is Your Infrastructure Affected by CVE-2026-92598?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.