medium5.3
CVE-2026-45755
Symfony's Mailtrap Mailer Webhook Parser Never Verifies the X-Mt-Signature HMAC — Unauthenticated Webhook Event Injection
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | symfony/mailtrap-mailer | >= 7.2.0, < 7.4.12 | 7.4.12 |
| composer | symfony/symfony | >= 7.2.0, < 7.4.12 | 7.4.12 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Sensiolabs | Symfony | from 7.2.0 before 7.4.12 from 8.0.0 before 8.0.12 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-59f3-vp2f-mp9w
- https://github.com/symfony/symfony/security/advisories/GHSA-59f3-vp2f-mp9w
- https://github.com/symfony/symfony/commit/4e0467e4e182cf2e704a3d9e1bc1a6be65d52ab8
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/mailtrap-mailer/CVE-2026-45755.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45755.yaml
- https://symfony.com/cve-2026-45755
- https://github.com/symfony/symfony/releases/tag/v7.4.12
- https://github.com/symfony/symfony/releases/tag/v8.0.12