Omnisend for WooCommerce <= 1.18.0 - Unauthenticated Omnisend Account Takeover via Predictable Connect Token
| CVE | CVE-2026-42668 |
|---|---|
| CVSS | 7.5 (High) |
| Publicly Published | May 13, 2026 |
| Last Updated | May 13, 2026 |
| Researcher |
0xzenko
|
Description
The Omnisend for WooCommerce plugin for WordPress is vulnerable to an unauthenticated account takeover via insufficiently random values in versions up to, and including, 1.18.0. This is due to the generate_install_url() function deriving the OAuth connect token solely from the Unix timestamp at page-load time (hash('sha256', time())), which yields only ~86,400 distinct values per day and is trivially brute-forceable. This makes it possible for unauthenticated attackers to predict the connect token, authenticate to the POST /wp-json/omnisend-api/v1/connect REST endpoint, and replace the store's omnisend_api_key and brand_id with attacker-supplied values, redirecting all customer PII synchronization, order webhooks, and marketing communications to the attacker's Omnisend account.
References
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- patchstack.com
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Vulnerability Details for Email Marketing for WooCommerce by Omnisend
| Software Type | Plugin |
|---|---|
| Software Slug | omnisend-connect (view on wordpress.org) |
| Patched? | Yes |
| Remediation | Update to version 1.18.1, or a newer patched version |
| Affected Version |
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| Patched Version |
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Recent vulnerabilities in Email Marketing for WooCommerce by Omnisend
| # | Title | CVE ID | CVSS | Researchers | Date |
|---|---|---|---|---|---|
| 1 | Email Marketing for WooCommerce by Omnisend <= 1.19.0 - Missing Authorization | CVE-2026-57632 | June 26, 2026 | ||
| 2 | Email Marketing for WooCommerce by Omnisend <= 1.14.3 - Cross-Site Request Forgery | CVE-2024-32101 | Dhabaleshwar Das | April 11, 2024 | |
| 3 | Email Marketing for WooCommerce by Omnisend <= 1.13.8 - Sensitive Information Exposure | CVE-2023-47244 | Kévin Mosbahi (Mika) | November 7, 2023 |
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