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OpenAdvisories
Medium · 6.9 CVE-2026-45755 EUVD-2026-44361GHSA-59f3-vp2f-mp9w

Symfony: Mailtrap Mailer Webhook Parser Never Verifies the X-Mt-Signature HMAC — Unauthenticated Webhook Event Injection

Published Jul 14, 2026 · Updated Jul 14, 2026 · Assigned by GitHub_M

Description

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 products

VendorProductAffectedFixed
symfony symfony >= 7.2.0, < 7.4.12, >= 8.0.0-BETA1, < 8.0.12 —
/mailtrap-mailer mailtrap-mailer >= 7.2.0, < 7.4.12, >= 8.0.0-BETA1, < 8.0.12 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 symfony 7.4.12+dfsg-1 —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 symfony No fix yet —
Ubuntu 26.04 LTS symfony No fix yet —
Ubuntu 25.10 symfony No fix yet —
Ubuntu 16.04 LTS symfony No fix yet —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 24.04 LTS symfony No fix yet —
Ubuntu Pro 22.04 LTS symfony No fix yet —
Ubuntu Pro 20.04 LTS symfony No fix yet —
Ubuntu Pro 18.04 LTS symfony No fix yet —

Affected packages

EcosystemPackageAffectedFixedRecord
Packagist symfony/mailtrap-mailer >= 7.2.0, < 7.4.12 7.4.12 GHSA-59f3-vp2f-mp9w
Packagist symfony/mailtrap-mailer >= 8.0.0, < 8.0.12 8.0.12 GHSA-59f3-vp2f-mp9w
Packagist symfony/symfony >= 7.2.0, < 7.4.12 7.4.12 GHSA-59f3-vp2f-mp9w
Packagist symfony/symfony >= 8.0.0, < 8.0.12 8.0.12 GHSA-59f3-vp2f-mp9w

References