CVE record
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 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.
CVE evidence
Known exploitation
Not listed in fetched KEV catalog
Absence from the fetched catalog does not establish that exploitation has not occurred.
Severity
moderate
CVSS 6.9 · CVSS_V4
Affected packages
2
Supported package records returned by OSV. Vendor and product names are not used to infer matches.
OSV package mapping
Affected open-source packages
| Package | Ecosystem | Fixed versions |
|---|---|---|
| symfony/mailtrap-mailer | composer | 7.4.12, 8.0.12 |
| symfony/symfony | composer | 7.4.12, 8.0.12 |