← Back to CVE Explorer

CVE-2026-121623

Full vulnerability record from the local CVENow database.

Description

The Symfony Serializer component DataUriNormalizer::denormalize() matches the data: scheme with a case-sensitive regular expression, allowing a value with an uppercase scheme, such as DATA:,/../../../etc/passwd, to bypass it, resulting in Arbitrary Local File Read through Path Traversal in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11. A value whose scheme is not lowercase data: are treated as a local file path and opened instead of being decoded as inline data, so the resulting File, \SplFileInfo, or \SplFileObject points at a file on the server, which the application then handles as the uploaded content. Any endpoint that deserializes untrusted input into one of these types is affected. FrameworkBundle registers DataUriNormalizer ahead of ObjectNormalizer by default. A single request with a crafted DATA: value is enough to read arbitrary local files that the application can access, with no authentication needed if the endpoint is public.

Severity
HIGH
CVSS score
8.2 (v4.0)
Vulnerability status
Received
Source identifier
596c5446-0ce5-4ba2-aa66-48b3b757a647
Published
2026-11-06 16:17:52.780000
Last modified
2026-11-06 16:17:52.780000
View original CVE JSON
{
  "id": "CVE-2026-121623",
  "sourceIdentifier": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
  "published": "2026-11-06T16:17:52.780",
  "lastModified": "2026-11-06T16:17:52.780",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Symfony Serializer component DataUriNormalizer::denormalize() matches the data: scheme with a case-sensitive regular expression, allowing a value with an uppercase scheme, such as DATA:,/../../../etc/passwd, to bypass it, resulting in Arbitrary Local File Read through Path Traversal in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.\n\nA value whose scheme is not lowercase data: are treated as a local file path and opened instead of being decoded as inline data, so the resulting File, \\SplFileInfo, or \\SplFileObject points at a file on the server, which the application then handles as the uploaded content.\n\nAny endpoint that deserializes untrusted input into one of these types is affected. FrameworkBundle registers DataUriNormalizer ahead of ObjectNormalizer by default. A single request with a crafted DATA: value is enough to read arbitrary local files that the application can access, with no authentication needed if the endpoint is public."
    }
  ],
  "affected": [
    {
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
      "affectedData": [
        {
          "vendor": "sensiolabs",
          "product": "symfony",
          "defaultStatus": "unaffected",
          "collectionURL": "https://packagist.org/packages/symfony/serializer",
          "packageName": "symfony/serializer",
          "modules": [
            "Symfony\\Component\\Serializer\\Normalizer\\DataUriNormalizer::denormalize()"
          ],
          "repo": "https://github.com/symfony/serializer",
          "versions": [
            {
              "version": "0",
              "lessThan": "5.4.56",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6.0.0",
              "lessThan": "6.4.50",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "7.0.0",
              "lessThan": "7.4.23",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8.0.0",
              "lessThan": "8.1.11",
              "versionType": "git",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 8.2,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        },
        {
          "lang": "en",
          "value": "CWE-73"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/symfony/symfony/commit/a0c551861ac23f888dfe6d1157ca78f4e220f3b7",
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647"
    },
    {
      "url": "https://github.com/symfony/symfony/security/advisories/GHSA-pxj9-jh84-vhm5",
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647"
    }
  ]
}