Vulnerability in Nodemailer (CVE-2026-92597)
Summary
Vulnerability in Nodemailer (CVE-2026-92597). Confidential information can be exposed externally. Mitigation: upgrade to 9.1.0 or later.
Original description
The description as published by the source.
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 user@good-corp.com(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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-92597 has been found in Nodemailer.
Confidential information can be exposed externally. CVSS score: 6.5/10.
What to do: upgrade Nodemailer to 9.1.0 or later.
If unsure, ask your IT team or search "Nodemailer CVE-2026-92597" on the vendor's site.
CVE-2026-92597 (Nodemailer) — CWE-436 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 9.1.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-436) exists in Nodemailer.
Check the vendor advisory for the affected versions of Nodemailer.
Severity: Medium (CVSS 6.5/10). Confidential information can be exposed externally.
Update to 9.1.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Nodemailer' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'Nodemailer' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Nodemailerを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade Nodemailer to 9.1.0ステージング環境で 9.1.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web github.com
- web github.com
- web vulncheck.com
- web nvd.nist.gov
- web github.com