CVE-2026-48747
Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 7.4.13 and 8.0.13, MailomatRequestParser::validateSignature() parsed X-MOM-Webhook-Signature as algo=signature and passed the request-selected algorithm to hash_hmac(), allowing a signature algorithm downgrade instead of enforcing Mailomat's documented SHA-256 webhook signature. This issue is fixed in versions 7.4.13 and 8.0.13.
| CWE | CWE-347 CWE-757 |
| Vendor | symfony |
| Product | symfony |
| Published | Jul 14, 2026 |
| Last Updated | Jul 15, 2026 |
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Affected Versions
symfony / symfony
>= 7.2.0, < 7.4.12 >= 8.0.0-BETA1, < 8.0.13
symfony / mailomat-mailer
>= 7.2.0, < 7.4.12 >= 8.0.0-BETA1, < 8.0.13
References
github.com: https://github.com/symfony/symfony/security/advisories/GHSA-rrj9-5q2j-4gvr github.com: https://github.com/symfony/symfony/commit/bdfe9fe0d94d33dfaca0bc2fe0b00b54767b0c88 github.com: https://github.com/symfony/symfony/releases/tag/v7.4.13 github.com: https://github.com/symfony/symfony/releases/tag/v8.0.13