Cloudanix VulnDB

CVE-2026-45754

High · 7.5

Symfony's Mailjet Mailer Webhook Parser Never Verifies the Configured Secret — Unauthenticated Webhook Event Injection

CVSS

7.5

EPSS

0.4%

Published

May 28, 2026

CISA due date

—

The record

The Mailjet mailer bridge and the LOX24 SMS notifier bridge both ship webhook request parsers used to authenticate and decode the event callbacks each provider POSTs to an application's webhook endpoint. Their `doParse(Request $request, #[\SensitiveParameter] string $secret)` methods receive the configured webhook secret but never read it; they convert and return the payload unconditionally. As a result, an application that wires up either webhook endpoint accepts **any** POST to that URL, even when a webhook secret is configured (the recommended setup). An attacker who knows the endpoint exists can submit forged event payloads, fake bounce / blocked / spam / open / click / delivery events, leading to suppression-list corruption, delivery-metrics fraud, etc.

Affected packages

Ecosystem Package Introduced Fixed

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