Missing Authentication for Critical Function Affecting symfony/mailtrap-mailer package, versions <7.4.12>=8.0.0-BETA1, <8.0.12
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published24 May 2026
- disclosed20 May 2026
- creditHimanshu Anand
Introduced: 20 May 2026
CVE-2026-45755 (opens in a new tab)How to fix?
Upgrade symfony/mailtrap-mailer to version 7.4.12, 8.0.12 or higher.
Overview
symfony/mailtrap-mailer is a Symfony Mailtrap Mailer Bridge
Affected versions of this package are vulnerable to Missing Authentication for Critical Function via the doParse() webhook request parser in the Mailtrap mailer bridge. An attacker can submit forged webhook events because the parser ignores the X-Mt-Signature HMAC header and never validates the configured webhook secret, allowing unauthenticated POST requests to be processed as legitimate Mailtrap callbacks.
This can lead to falsified delivery, bounce, open, click, or spam events, resulting in suppression-list corruption and delivery-metrics manipulation.