CVE-2026-39823

{
  "id": "CVE-2026-39823",
  "sourceIdentifier": "[email protected]",
  "published": "2026-05-07T20:16:43.290",
  "lastModified": "2026-10-26T20:10:00.160",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "CVE-2026-27142 fixed a vulnerability in which URLs were not correctly escaped inside of a <meta> tag's <content> attribute. If the URL content were to insert ASCII whitespaces around the '=' rune inside of the <content> attribute, the escaper would fail to similarly escape it, leading to XSS."
    },
    {
      "lang": "es",
      "value": "CVE-2026-27142 corrigió una vulnerabilidad en la que las URL no se escapaban correctamente dentro del atributo [content] de una etiqueta [meta]. Si el contenido de la URL insertara espacios en blanco ASCII alrededor del carácter ’=’ dentro del atributo [content], el mecanismo de escape no lograría escaparlo de manera similar, lo que llevaría a XSS."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Go standard library",
          "product": "html/template",
          "defaultStatus": "unaffected",
          "collectionURL": "https://pkg.go.dev",
          "packageName": "html/template",
          "programRoutines": [
            {
              "name": "tMetaContent"
            },
            {
              "name": "Template.Execute"
            },
            {
              "name": "Template.ExecuteTemplate"
            }
          ],
          "versions": [
            {
              "version": "0",
              "lessThan": "1.25.10",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "1.26.0-0",
              "lessThan": "1.26.3",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
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      {
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        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "baseScore": 6.1,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "CHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.7
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-08T14:05:34.310805Z",
          "id": "CVE-2026-39823",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ]
    }
  ],
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  "references": [
    {
      "url": "https://go.dev/cl/769920",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://go.dev/issue/78913",
      "source": "[email protected]",
      "tags": [
        "Issue Tracking"
      ]
    },
    {
      "url": "https://groups.google.com/g/golang-announce/c/qcCIEXso47M",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://pkg.go.dev/vuln/GO-2026-4982",
      "source": "[email protected]",
      "tags": [
        "Vendor Advisory"
      ]
    }
  ]
}