CVE-2026-48747

Summary

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.

Affected Software

VendorProductVersion RangeStatus
symfonysymfony>= 7.2.0, < 7.4.12affected
symfonysymfony>= 8.0.0-BETA1, < 8.0.13affected
symfonymailomat-mailer>= 7.2.0, < 7.4.12affected
symfonymailomat-mailer>= 8.0.0-BETA1, < 8.0.13affected

Weaknesses

  • CWE-347: CWE-347: Improper Verification of Cryptographic Signature
  • CWE-757: CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')

References