FKIE_CVE-2026-123824

Vulnerability from fkie_nvd - Published: 2026-11-06 18:18 - Updated: 2026-11-06 21:40
Severity
6.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Summary
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. XmlUtils::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. Applications 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.
References
596c5446-0ce5-4ba2-aa66-48b3b757a647https://github.com/symfony/symfony/commit/334ef21a6039355c05b123e7df60699be0e28da3
596c5446-0ce5-4ba2-aa66-48b3b757a647https://github.com/symfony/symfony/security/advisories/GHSA-5jff-8h8q-r5qx
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://packagist.org/packages/symfony/config",
          "defaultStatus": "unaffected",
          "modules": [
            "Symfony\\Component\\Config\\Util\\XmlUtils::parse"
          ],
          "packageName": "symfony/config",
          "product": "symfony",
          "repo": "https://github.com/symfony/config",
          "vendor": "sensiolabs",
          "versions": [
            {
              "lessThan": "5.4.56",
              "status": "affected",
              "version": "0",
              "versionType": "git"
            },
            {
              "lessThan": "6.4.50",
              "status": "affected",
              "version": "6.0.0",
              "versionType": "git"
            },
            {
              "lessThan": "7.4.23",
              "status": "affected",
              "version": "7.0.0",
              "versionType": "git"
            },
            {
              "lessThan": "8.1.11",
              "status": "affected",
              "version": "8.0.0",
              "versionType": "git"
            }
          ]
        }
      ],
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Symfony Config component\u00a0XmlUtils::parse()\u00a0enables DTD validation before rejecting documents that carry a doctype, allowing\u00a0XML 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\u00a0file://\u00a0entity.\nXmlUtils::parse()\u00a0sets\u00a0$dom-\u003evalidateOnParse = true\u00a0before calling\u00a0loadXML()\u00a0and only rejects documents carrying a doctype afterwards. Enabling DTD validation makes libxml resolve external entities during\u00a0loadXML(), and\u00a0LIBXML_NONET\u00a0blocks\u00a0http://\u00a0but not\u00a0file://, so a\u00a0file://\u00a0entity 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\u00a0s3://, a parameter entity can also send the content of a local file to an external server.\u00a0This is the same issue as CVE-2026-45071, which was fixed in the\u00a0DomCrawler\u00a0component but not in\u00a0Config.\n\nApplications are affected if they pass untrusted XML to\u00a0XmlUtils::parse()\u00a0directly. 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."
    }
  ],
  "id": "CVE-2026-123824",
  "lastModified": "2026-11-06T21:40:43.450",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 6.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.4,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 2.3,
          "baseSeverity": "LOW",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "LOW",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "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",
          "version": "4.0",
          "vulnAvailabilityImpact": "LOW",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "LOW",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-123824",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-11-06T20:28:48.074549Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-11-06T18:18:05.140",
  "references": [
    {
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
      "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"
    }
  ],
  "sourceIdentifier": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-611"
        }
      ],
      "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647",
      "type": "Secondary"
    }
  ]
}



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