{
 "id": "WPSEC-2026-0670",
 "url": "https://wpsec.com/vuln/WPSEC-2026-0670/",
 "json_url": "https://wpsec.com/vuln/WPSEC-2026-0670/advisory.json",
 "markdown_url": "https://wpsec.com/vuln/WPSEC-2026-0670/index.md",
 "title": "Constant Contact Forms <= 2.22.0 - Improper Authentication to Unauthenticated Mailing List Subscription of Arbitrary Users via Login Opt-in",
 "description": "The Constant Contact Forms plugin for WordPress is vulnerable to Improper Authentication in all versions up to, and including, 2.22.0. The login opt-in handler ran before WordPress verified the submitted password, did not check whether the login opt-in was enabled, and identified the account by the submitted username alone. This makes it possible for unauthenticated attackers who know a username to subscribe that user's email address to the site's Constant Contact mailing lists without the user's consent.",
 "plugin": {
  "slug": "constant-contact-forms",
  "name": "Constant Contact Forms",
  "full_name": "Constant Contact Forms",
  "wordpress_org": "https://wordpress.org/plugins/constant-contact-forms/",
  "advisories_url": "https://wpsec.com/vuln/plugin/constant-contact-forms/",
  "attacksurface": "https://attacksurface.wpsec.com/plugin/constant-contact-forms"
 },
 "type": "AUTHBYPASS",
 "cwe": [
  "CWE-287"
 ],
 "cve": [],
 "cvss": {
  "version": "3.1",
  "score": 5.3,
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
  "severity": "Medium"
 },
 "affected": {
  "ranges": [
   {
    "from": null,
    "from_inclusive": true,
    "to": "2.22.1",
    "to_inclusive": false
   }
  ],
  "text": [
   "all versions before 2.22.1"
  ]
 },
 "introduced_in": null,
 "fixed_in": "2.22.1",
 "remediation": "Update to 2.22.1 or later.",
 "fix_released": "2026-10-07T16:49:58+00:00",
 "published": "2026-10-08T17:43:55+00:00",
 "updated": "2026-10-07T19:15:10.052544+00:00",
 "also_published_as": null,
 "references": [
  "https://wpsec.com/vuln/WPSEC-2026-0670/",
  "https://plugins.svn.wordpress.org/constant-contact-forms/tags/2.22.1/",
  "https://wordpress.org/plugins/constant-contact-forms/"
 ],
 "attacksurface_url": "https://attacksurface.wpsec.com/plugin/constant-contact-forms",
 "source": "WPSec",
 "license": {
  "name": "CC BY 4.0",
  "url": "https://creativecommons.org/licenses/by/4.0/"
 },
 "usage": {
  "plugin": "Medium",
  "affected_versions": "Medium",
  "as_of": "2026-10-08"
 }
}