CVE-2026-27142 (GCVE-0-2026-27142)

Vulnerability from cvelistv5 – Published: 2026-03-06 21:28 – Updated: 2026-03-16 15:21
VLAI
Title
URLs in meta content attribute actions are not escaped in html/template
Summary
Actions which insert URLs into the content attribute of HTML meta tags are not escaped. This can allow XSS if the meta tag also has an http-equiv attribute with the value "refresh". A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be used to disable escaping URLs in actions in the meta content attribute which follow "url=" by setting htmlmetacontenturlescape=0.
Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
Go
References
Impacted products
Vendor Product Version
Go standard library html/template Affected: 0 , < 1.25.8 (semver)
Affected: 1.26.0-0 , < 1.26.1 (semver)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 6.1,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "LOW",
              "privilegesRequired": "NONE",
              "scope": "CHANGED",
              "userInteraction": "REQUIRED",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-27142",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-16T15:21:11.058826Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-16T15:21:14.465Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "html/template",
          "product": "html/template",
          "programRoutines": [
            {
              "name": "tTag"
            },
            {
              "name": "escaper.escapeAction"
            },
            {
              "name": "Template.Execute"
            },
            {
              "name": "Template.ExecuteTemplate"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.8",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.1",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Actions which insert URLs into the content attribute of HTML meta tags are not escaped. This can allow XSS if the meta tag also has an http-equiv attribute with the value \"refresh\". A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be used to disable escaping URLs in actions in the meta content attribute which follow \"url=\" by setting htmlmetacontenturlescape=0."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-06T21:28:14.674Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk"
        },
        {
          "url": "https://go.dev/issue/77954"
        },
        {
          "url": "https://go.dev/cl/752081"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-4603"
        }
      ],
      "title": "URLs in meta content attribute actions are not escaped in html/template"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-27142",
    "datePublished": "2026-03-06T21:28:14.674Z",
    "dateReserved": "2026-02-17T19:57:28.435Z",
    "dateUpdated": "2026-03-16T15:21:14.465Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-27142",
      "date": "2026-06-09",
      "epss": "0.00013",
      "percentile": "0.02036"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-27142\",\"sourceIdentifier\":\"security@golang.org\",\"published\":\"2026-03-06T22:16:01.177\",\"lastModified\":\"2026-04-21T14:30:01.380\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Actions which insert URLs into the content attribute of HTML meta tags are not escaped. This can allow XSS if the meta tag also has an http-equiv attribute with the value \\\"refresh\\\". A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be used to disable escaping URLs in actions in the meta content attribute which follow \\\"url=\\\" by setting htmlmetacontenturlescape=0.\"},{\"lang\":\"es\",\"value\":\"Acciones que insertan URLs en el atributo content de las etiquetas meta HTML no se escapan. Esto puede permitir XSS si la etiqueta meta tambi\u00e9n tiene un atributo http-equiv con el valor \u0027refresh\u0027. Se ha a\u00f1adido una nueva configuraci\u00f3n GODEBUG, htmlmetacontenturlescape, que se puede usar para deshabilitar el escape de URLs en acciones en el atributo content de las etiquetas meta que siguen a \u0027url=\u0027 al establecer htmlmetacontenturlescape=0.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"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}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"1.25.8\",\"matchCriteriaId\":\"2D293CC0-B163-4E62-B985-52FB6ECA64C5\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:1.26.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"A40FE3CB-0D03-462B-8A19-4DF1920ABE82\"}]}]}],\"references\":[{\"url\":\"https://go.dev/cl/752081\",\"source\":\"security@golang.org\",\"tags\":[\"Mailing List\"]},{\"url\":\"https://go.dev/issue/77954\",\"source\":\"security@golang.org\",\"tags\":[\"Issue Tracking\"]},{\"url\":\"https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk\",\"source\":\"security@golang.org\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://pkg.go.dev/vuln/GO-2026-4603\",\"source\":\"security@golang.org\",\"tags\":[\"Vendor Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 6.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"REQUIRED\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"LOW\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-27142\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-16T15:21:11.058826Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-10T13:38:17.936Z\"}}], \"cna\": {\"title\": \"URLs in meta content attribute actions are not escaped in html/template\", \"affected\": [{\"vendor\": \"Go standard library\", \"product\": \"html/template\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"1.25.8\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"1.26.0-0\", \"lessThan\": \"1.26.1\", \"versionType\": \"semver\"}], \"packageName\": \"html/template\", \"collectionURL\": \"https://pkg.go.dev\", \"defaultStatus\": \"unaffected\", \"programRoutines\": [{\"name\": \"tTag\"}, {\"name\": \"escaper.escapeAction\"}, {\"name\": \"Template.Execute\"}, {\"name\": \"Template.ExecuteTemplate\"}]}], \"references\": [{\"url\": \"https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk\"}, {\"url\": \"https://go.dev/issue/77954\"}, {\"url\": \"https://go.dev/cl/752081\"}, {\"url\": \"https://pkg.go.dev/vuln/GO-2026-4603\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Actions which insert URLs into the content attribute of HTML meta tags are not escaped. This can allow XSS if the meta tag also has an http-equiv attribute with the value \\\"refresh\\\". A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be used to disable escaping URLs in actions in the meta content attribute which follow \\\"url=\\\" by setting htmlmetacontenturlescape=0.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"description\": \"CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"shortName\": \"Go\", \"dateUpdated\": \"2026-03-06T21:28:14.674Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-27142\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-03-16T15:21:14.465Z\", \"dateReserved\": \"2026-02-17T19:57:28.435Z\", \"assignerOrgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"datePublished\": \"2026-03-06T21:28:14.674Z\", \"assignerShortName\": \"Go\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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

Author Source Type Date Other

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.