CVE-2026-48747 (GCVE-0-2026-48747)

Vulnerability from cvelistv5 – Published: 2026-07-14 19:16 – Updated: 2026-07-14 19:16
VLAI
Title
Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade
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.
Severity
6.3 (Medium)
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CWE
  • CWE-347 - Improper Verification of Cryptographic Signature
  • CWE-757 - Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')
Assigner
References
Impacted products
Vendor Product Version
symfony symfony Affected: >= 7.2.0, < 7.4.12
Affected: >= 8.0.0-BETA1, < 8.0.13
Create a notification for this product.
symfony mailomat-mailer Affected: >= 7.2.0, < 7.4.12
Affected: >= 8.0.0-BETA1, < 8.0.13
Create a notification for this product.
Show details on NVD website
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        }
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      "metrics": [
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            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
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          "name": "https://github.com/symfony/symfony/security/advisories/GHSA-rrj9-5q2j-4gvr",
          "tags": [
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        }
      ],
      "source": {
        "advisory": "GHSA-rrj9-5q2j-4gvr",
        "discovery": "UNKNOWN"
      },
      "title": "Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade"
    }
  },
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    "cveId": "CVE-2026-48747",
    "datePublished": "2026-07-14T19:16:24.327Z",
    "dateReserved": "2026-05-22T19:10:35.747Z",
    "dateUpdated": "2026-07-14T19:16:24.327Z",
    "state": "PUBLISHED"
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  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.