CVE-2026-123824

{
  "id": "CVE-2026-123824",
  "sourceIdentifier": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
  "published": "2026-11-06T18:18:05.140",
  "lastModified": "2026-11-06T18:18:05.140",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Symfony Config component XmlUtils::parse() enables DTD validation before rejecting documents that carry a doctype, allowing XML external entity (XXE) injection 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 remote attacker who can supply XML to this method can determine whether local files exist, cause a denial of service, and, in some configurations, exfiltrate local file content via a crafted XML document whose doctype declares an external file:// entity.\nXmlUtils::parse() sets $dom->validateOnParse = true before calling loadXML() and only rejects documents carrying a doctype afterwards. Enabling DTD validation makes libxml resolve external entities during loadXML(), and LIBXML_NONET blocks http:// but not file://, so a file:// entity is read from disk before the doctype rejection runs. The content of the file is not returned to the caller, but the distinct libxml error for a missing path reveals whether a file exists, and an entity pointing at a large or slow file causes a denial of service. If the application registers a network-capable stream wrapper such as s3://, a parameter entity can also send the content of a local file to an external server. This is the same issue as CVE-2026-45071, which was fixed in the DomCrawler component but not in Config.\n\nApplications are affected if they pass untrusted XML to XmlUtils::parse() directly. The Symfony components that call it process developer-provided or operator-configured sources, such as configuration files and the XLIFF documents fetched by the translation providers."
    }
  ],
  "affected": [
    {
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
      "affectedData": [
        {
          "vendor": "sensiolabs",
          "product": "symfony",
          "defaultStatus": "unaffected",
          "collectionURL": "https://packagist.org/packages/symfony/config",
          "packageName": "symfony/config",
          "modules": [
            "Symfony\\Component\\Config\\Util\\XmlUtils::parse"
          ],
          "repo": "https://github.com/symfony/config",
          "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:L/UI:N/VC:L/VI:L/VA:L/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": 2.3,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "LOW",
          "vulnAvailabilityImpact": "LOW",
          "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-611"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/symfony/symfony/commit/334ef21a6039355c05b123e7df60699be0e28da3",
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647"
    },
    {
      "url": "https://github.com/symfony/symfony/security/advisories/GHSA-5jff-8h8q-r5qx",
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647"
    }
  ]
}