CVE-2026-92597

MEDIUMPre-NVD 6.56.5—
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
Trending — 4 sources updated this week
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: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Nodemailer versions >= 6.9.16 and < 9.1.0 mis-parse RFC 5322 comments in email addresses: in lib/addressparser, a comment closed immediately before a non-break character causes the tokenizer to concatenate the atoms surrounding the comment instead of treating the comment as folding whitespace that terminates the domain. A recipient address such as [email protected](x)evil.com is therefore read by Nodemailer as the single domain good-corp.comevil.com (registrable domain comevil.com, which an attacker can register) and used for both the SMTP envelope (RCPT TO) and the emitted To:/From: headers, while a conformant RFC 5322 parser terminates the domain at the comment and reads good-corp.com. An application that validates the recipient domain with a strict RFC 5322 parser (without inspecting parse defects) or a naive prefix/substring allow-list and then hands the raw address to Nodemailer can be induced to deliver mail to a domain the attacker controls. Fixed in 9.1.0.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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 computed
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 17, 2026

Advisory Details (3)

Auto-updated Sep 16, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
generic

Nodemailer before 9.1.0 Email Domain Validation Bypass via RFC 5322 Comment | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nodemailer-before-9.1.0-email-domain-validation-bypass-via-rfc-5322-comment
github_commit Patch Available

commit 902b63e (nodemailer/nodemailer)

Patch available: nodemailer/nodemailer v9.1.0 (contains commit 902b63e)

https://github.com/nodemailer/nodemailer/commit/902b63e
github Patch Available🟡 PoC Available

Recipient-domain validation bypass via RFC 5322 comment mis-parsing 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-cc9r-2j5m-2m83

Vendor Advisories for CVE-2026-92597(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—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.

  1. 2026-09-18 21:36 UTCEG score recompute
  2. 2026-09-18 21:36 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-17 20:27 UTCEG score recompute
  5. 2026-09-17 20:27 UTCGHSA enrichment
  6. 2026-09-17 19:32 UTCEPSS rescore
  7. 2026-09-17 19:31 UTCEG score recompute
  8. 2026-09-17 19:31 UTCGHSA enrichment
  9. 2026-09-16 22:25 UTCEG score recompute
  10. 2026-09-16 21:54 UTCEG score recompute
  11. 2026-09-16 21:54 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-92597?
CVE-2026-92597 is a medium vulnerability published on September 16, 2026. Nodemailer versions >= 6.9.16 and < 9.1.0 mis-parse RFC 5322 comments in email addresses: in lib/addressparser, a comment closed immediately before a non-break character causes the tokenizer to concatenate the atoms surrounding the comment instead of treating the comment as folding whitespace that…
When was CVE-2026-92597 disclosed?
CVE-2026-92597 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-2026-92597 actively exploited?
CVE-2026-92597 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 82.5% of all scored CVEs.
What is the CVSS score of CVE-2026-92597?
CVE-2026-92597 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-92597?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-92597, 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

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