CVE-2026-8630 (GCVE-0-2026-8630)
Vulnerability from cvelistv5
Published
2026-08-23 13:34
Modified
2026-08-26 18:07
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Summary
justhtml before 1.12.0 (versions <= 1.11.0) contains a mutation cross-site scripting (mXSS) vulnerability in the serialization of raw-text elements such as <style> and <script>. When a DOM tree is processed by sanitize_dom() using a custom policy that keeps these elements, text nodes inside them are serialized literally without escaping, allowing attacker-controlled text containing the matching closing tag sequence to break out of the raw-text context and inject arbitrary HTML into the serialized output. The default sanitization policy is not affected because it drops the contents of style and script.
Impacted products
Vendor Product Version
EmilStenstrom justhtml Version: 0   
Create a notification for this product.
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-8630",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-26T18:06:49.331214Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-26T18:07:00.039Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:pypi/justhtml",
          "product": "justhtml",
          "vendor": "EmilStenstrom",
          "versions": [
            {
              "lessThan": "1.12.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "1.12.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "offset"
        }
      ],
      "datePublic": "2026-03-18T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "justhtml before 1.12.0 (versions \u003c= 1.11.0) contains a mutation cross-site scripting (mXSS) vulnerability in the serialization of raw-text elements such as \u003cstyle\u003e and \u003cscript\u003e. When a DOM tree is processed by sanitize_dom() using a custom policy that keeps these elements, text nodes inside them are serialized literally without escaping, allowing attacker-controlled text containing the matching closing tag sequence to break out of the raw-text context and inject arbitrary HTML into the serialized output. The default sanitization policy is not affected because it drops the contents of style and script."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.1,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "LOW",
            "userInteraction": "ACTIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS"
        },
        {
          "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"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-23T13:34:14.556Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Security Advisory (GHSA-qvc2-mg72-jjhx)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-qvc2-mg72-jjhx"
        },
        {
          "name": "VulnCheck Advisory: justhtml before 1.12.0 Mutation XSS via Raw Text Elements",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/justhtml-before-mutation-xss-via-raw-text-elements"
        }
      ],
      "title": "justhtml before 1.12.0 Mutation XSS via Raw Text Elements",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-8630",
    "datePublished": "2026-08-23T13:34:14.556Z",
    "dateReserved": "2026-05-14T18:57:10.898Z",
    "dateUpdated": "2026-08-26T18:07:00.039Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-8630\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-26T18:06:49.331214Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-08-26T18:06:55.073Z\"}}], \"cna\": {\"title\": \"justhtml before 1.12.0 Mutation XSS via Raw Text Elements\", \"credits\": [{\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"offset\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 5.1, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"ACTIVE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"LOW\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"LOW\", \"vulnConfidentialityImpact\": \"NONE\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}}, {\"format\": \"CVSS\", \"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\"}}], \"affected\": [{\"vendor\": \"EmilStenstrom\", \"product\": \"justhtml\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"1.12.0\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"1.12.0\", \"versionType\": \"semver\"}], \"packageURL\": \"pkg:pypi/justhtml\", \"defaultStatus\": \"unaffected\"}], \"datePublic\": \"2026-03-18T00:00:00.000Z\", \"references\": [{\"url\": \"https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-qvc2-mg72-jjhx\", \"name\": \"GitHub Security Advisory (GHSA-qvc2-mg72-jjhx)\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://www.vulncheck.com/advisories/justhtml-before-mutation-xss-via-raw-text-elements\", \"name\": \"VulnCheck Advisory: justhtml before 1.12.0 Mutation XSS via Raw Text Elements\", \"tags\": [\"third-party-advisory\"]}], \"x_generator\": {\"engine\": \"vulncheck-endgame\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"justhtml before 1.12.0 (versions \u003c= 1.11.0) contains a mutation cross-site scripting (mXSS) vulnerability in the serialization of raw-text elements such as \u003cstyle\u003e and \u003cscript\u003e. When a DOM tree is processed by sanitize_dom() using a custom policy that keeps these elements, text nodes inside them are serialized literally without escaping, allowing attacker-controlled text containing the matching closing tag sequence to break out of the raw-text context and inject arbitrary HTML into the serialized output. The default sanitization policy is not affected because it drops the contents of style and script.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-79\", \"description\": \"Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"83251b91-4cc7-4094-a5c7-464a1b83ea10\", \"shortName\": \"VulnCheck\", \"dateUpdated\": \"2026-08-23T13:34:14.556Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-8630\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-26T18:07:00.039Z\", \"dateReserved\": \"2026-05-14T18:57:10.898Z\", \"assignerOrgId\": \"83251b91-4cc7-4094-a5c7-464a1b83ea10\", \"datePublished\": \"2026-08-23T13:34:14.556Z\", \"assignerShortName\": \"VulnCheck\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


Loading…

Loading…