CVE-2026-109516: Auth Bypass (CVSS 9.8)

Description

The Bot for Telegram on WooCommerce plugin for WordPress is vulnerable to Authentication Bypass leading to Account Takeover in all versions up to, and including, 1.3.0. The `/wp-json/woo-telegram/v1/main/` REST endpoint is registered with `permission_callback => '__return_true'` and performs no Telegram webhook signature verification, allowing an unauthenticated attacker to POST a forged bot update with a `message.chat.id` set to any WordPress login name; `bftow_get_user_system_id()` resolves this attacker-supplied value to the targeted account via `get_user_by('login', $tgId)` with no ownership proof, and writes a login token computed as `md5($_SERVER['HTTP_USER_AGENT'] . time())` — both inputs are fully attacker-controlled or bounded within seconds using the response's own `Date` header. The resulting token is redeemable at the unauthenticated, capability-check-free, and nonce-less `?action=bftow_create_order&bftow_token=` endpoint, which calls `wp_set_auth_cookie()` unconditionally via `login_user_by_id`, issuing a persistent authenticated session cookie for the targeted account to the attacker. This makes it possible for unauthenticated attackers to log in as any WordPress user, including administrators, given only that user's username.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0058

Probability of exploitation

0.48%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-287 Improper Authentication

References

Other References

https://plugins.trac.wordpress.org/browser/bot-for-telegram-on-woocommerce/tags/1.3.0/includes/BFTOW_Telegram.php#L91 https://plugins.trac.wordpress.org/browser/bot-for-telegram-on-woocommerce/tags/1.3.0/includes/BFTOW_Telegram.php#L98 https://plugins.trac.wordpress.org/browser/bot-for-telegram-on-woocommerce/tags/1.3.0/includes/BFTOW_User.php#L149 https://plugins.trac.wordpress.org/browser/bot-for-telegram-on-woocommerce/tags/1.3.0/includes/BFTOW_User.php#L44 https://plugins.trac.wordpress.org/browser/bot-for-telegram-on-woocommerce/tags/1.3.0/includes/BFTOW_User.php#L62 https://plugins.trac.wordpress.org/browser/bot-for-telegram-on-woocommerce/tags/1.3.0/includes/BFTOW_WooCommerce.php#L42 https://www.wordfence.com/threat-intel/vulnerabilities/id/1f6b73e0-c154-4bc4-90bc-0929053b77b0?source=cve

Frequently Asked Questions

What is CVE-2026-109516? +

The Bot for Telegram on WooCommerce plugin for WordPress is vulnerable to Authentication Bypass leading to Account Takeover in all versions up to, and including, 1.3.0. The `/wp-json/woo-telegram/v1/main/` REST endpoint is registered with `permission_callback => '__return_true'` and performs no Telegram webhook signature verification, allowing an unauthenticated attacker to POST a forged bot update with a `message.chat.id` set to any WordPress login name; `bftow_get_user_system_id()` resolves this attacker-supplied value to the targeted account via `get_user_by('login', $tgId)` with no ownership proof, and writes a login token computed as `md5($_SERVER['HTTP_USER_AGENT'] . time())` — both inputs are fully attacker-controlled or bounded within seconds using the response's own `Date` header. The resulting token is redeemable at the unauthenticated, capability-check-free, and nonce-less `?action=bftow_create_order&bftow_token=` endpoint, which calls `wp_set_auth_cookie()` unconditionally via `login_user_by_id`, issuing a persistent authenticated session cookie for the targeted account to the attacker. This makes it possible for unauthenticated attackers to log in as any WordPress user, including administrators, given only that user's username. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-109516? +

CVE-2026-109516 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0058, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-109516? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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