External risk intelligence

Bot for Telegram on WooCommerce Authentication Bypass Leads to Account Takeover

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-109516

The vulnerability affects a WordPress plugin designed to integrate WooCommerce with Telegram via public-facing REST API endpoints. Such plugins are commonly deployed on internet-accessible web servers to receive webhooks from third-party services. The exploited endpoints are network-reachable, making this a likely attack surface in standard web-based ecommerce configurations.

Authentication Bypass

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability exists in the Bot for Telegram on WooCommerce WordPress plugin that allows unauthenticated attackers to bypass authentication and take over any user account, including administrative accounts, by exploiting a weakness in how Telegram webhook updates are handled. This could lead to a complete compromise of WordPress sites using this plugin.

Website accounts can be taken over.
Protects against unauthorized administrative access.
Confirm plugin relevance and assess exposure.

Attack Path

How an attacker could exploit the issue

An attacker can bypass authentication by sending a specially crafted update to a specific Telegram bot endpoint. This allows them to impersonate any user, including administrators, by providing a username and a forged token. The system then grants the attacker an authenticated session, enabling them to take over the account.

No authentication required.
Send forged bot update to specific endpoint.
Full account takeover possible.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated attacker to impersonate any WordPress user, including administrators, by knowing their username. The attacker could then gain full control over the WordPress site by leveraging this impersonation.

WordPress user accounts and administrative access.
Authentication bypass via forged bot updates.
Full site compromise or unauthorized actions.

Operational Fix

Recommended remediation, mitigation, and detection steps

Security teams and platform owners are likely responsible for addressing this vulnerability. The first practical step is to identify all WordPress instances using the affected plugin, determine their reachability and business criticality, and locate the accountable application owner. Remediation planning should then be based on this risk assessment.

Application owners should prioritize this.
Verify plugin presence and configuration.
Plan remediation based on exposure.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the Bot for Telegram on WooCommerce plugin?

This software is a WordPress extension that connects an online store powered by WooCommerce to the Telegram messaging platform. It allows store owners to send notifications or interact with customers directly through Telegram bots by using automated webhooks to relay store events and updates.

What does CWE-287 mean for this CVE?

CWE-287 refers to improper authentication. In the context of CVE-2026-109516, the plugin fails to verify the identity of incoming requests. It blindly trusts forged data claiming to be a legitimate Telegram update, which allows the system to be tricked into granting full access to any user account without requiring a password or proof of ownership.

How does an attacker trigger this vulnerability?

An attacker sends a crafted request to the plugin’s REST API endpoint. The bug does not require any existing privileges. Notably, the vulnerability is not triggered by standard site traffic, but specifically by interacting with the plugin's webhook listener, which lacks the necessary security checks to validate incoming data packets.

Do I need to worry if my site is internal?

According to Halo Surface Signal, this plugin uses public-facing REST API endpoints to receive webhooks, making sites with internet-accessible web servers significantly more susceptible. If your instance is strictly internal and unreachable from the internet, the immediate risk of external exploitation is reduced, but the vulnerability remains a serious concern for any active installation.

How should I respond to this threat?

Your first step is to locate all WordPress instances running this plugin. Once identified, assess whether the site is accessible from the internet and who manages the application. Prioritize disabling or removing the plugin until a verified update is available, as the potential for unauthorized administrative access makes this a critical priority for site security.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.