CVE-2026-45755 — Symfony: Mailtrap Mailer Webhook Parser Never Verifies the X-Mt-Signature HMAC — Unauthenticated Webhook Event Injection
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 7.4.12 and 8.0.12, MailtrapRequestParser::doParse() received the confi…
Published: 2026-07-14 · CVSS: 6.9 · CVSS 4.0
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 7.4.12 and 8.0.12, MailtrapRequestParser::doParse() received the configured webhook secret but ignored the X-Mt-Signature HMAC header, allowing unauthenticated POST requests to inject forged Mailtrap delivery, bounce, open, click, or spam events. This issue is fixed in versions 7.4.12 and 8.0.12.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7