CVE Catalog

CVE-2026-48747

MediumCVSS 5.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.24%

15th percentile - higher than 15% of all known CVEs

Summary

A vulnerability in Symfony allows an attacker to downgrade the Mailomat webhook signature algorithm from SHA-256 to a weaker one by manipulating the X-MOM-Webhook-Signature header. The issue affects MailomatRequestParser::validateSignature() before versions 7.4.13 and 8.0.13.

Risk Assessment

An attacker can forge webhook signatures, leading to acceptance of unauthorized requests and potential data integrity compromise or execution of unintended actions in the application.

Recommendation

Immediately upgrade Symfony to version 7.4.13 or 8.0.13, which enforce the SHA-256 algorithm for Mailomat webhook signature verification.

Other vulnerabilities in Symfony

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS