CVE-2026-104828 (GCVE-0-2026-104828)
Vulnerability from cvelistv5
Published
2026-10-15 18:36
Modified
2026-10-21 01:04
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Summary
HtmlUnit Neko is an HtmlUnit adaptation of NekoHTML. Prior to 5.4.0, HTMLWriterFilter writes decoded TEXTAREA and TITLE character content without entity encoding because both elements are treated as special content. During a parse-and-serialize round trip, entity references inside these escapable raw-text elements are decoded by the parser and then emitted as raw markup by printCharacters(), changing the document's semantics. Applications that use htmlunit-neko in an HTML sanitizer, content filter, or other parse-transform-serialize pipeline can therefore turn attacker-controlled encoded text into executable markup when the output is rendered by a browser. This issue is fixed in version 5.4.0.
Impacted products
Vendor Product Version
HtmlUnit htmlunit-neko Version: < 5.4.0
Create a notification for this product.
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-104828",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-21T01:04:22.177553Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-21T01:04:51.279Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/HtmlUnit/htmlunit-neko/security/advisories/GHSA-39xg-prhf-8785"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "htmlunit-neko",
          "vendor": "HtmlUnit",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.4.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "HtmlUnit Neko is an HtmlUnit adaptation of NekoHTML. Prior to 5.4.0, HTMLWriterFilter writes decoded TEXTAREA and TITLE character content without entity encoding because both elements are treated as special content. During a parse-and-serialize round trip, entity references inside these escapable raw-text elements are decoded by the parser and then emitted as raw markup by printCharacters(), changing the document\u0027s semantics. Applications that use htmlunit-neko in an HTML sanitizer, content filter, or other parse-transform-serialize pipeline can therefore turn attacker-controlled encoded text into executable markup when the output is rendered by a browser. This issue is fixed in version 5.4.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-15T18:39:13.508Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/HtmlUnit/htmlunit-neko/security/advisories/GHSA-39xg-prhf-8785",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/HtmlUnit/htmlunit-neko/security/advisories/GHSA-39xg-prhf-8785"
        },
        {
          "name": "https://github.com/HtmlUnit/htmlunit-neko/commit/c165891e0753aef3e05f5daa6250d3e8d4ada3c0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/HtmlUnit/htmlunit-neko/commit/c165891e0753aef3e05f5daa6250d3e8d4ada3c0"
        },
        {
          "name": "https://github.com/HtmlUnit/htmlunit-neko/releases/tag/5.4.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/HtmlUnit/htmlunit-neko/releases/tag/5.4.0"
        }
      ],
      "source": {
        "advisory": "GHSA-39xg-prhf-8785",
        "discovery": "UNKNOWN"
      },
      "title": "HtmlUnit Neko: Mutation XSS (mXSS) in HTMLWriterFilter - TEXTAREA/TITLE entity decode without re-encode"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-104828",
    "datePublished": "2026-10-15T18:36:49.613Z",
    "dateReserved": "2026-10-02T14:17:09.335Z",
    "dateUpdated": "2026-10-21T01:04:51.279Z",
    "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-2026-104828\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-21T01:04:22.177553Z\"}}}], \"references\": [{\"url\": \"https://github.com/HtmlUnit/htmlunit-neko/security/advisories/GHSA-39xg-prhf-8785\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-21T01:04:41.920Z\"}}], \"cna\": {\"title\": \"HtmlUnit Neko: Mutation XSS (mXSS) in HTMLWriterFilter - TEXTAREA/TITLE entity decode without re-encode\", \"source\": {\"advisory\": \"GHSA-39xg-prhf-8785\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 7.2, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"LOW\"}}], \"affected\": [{\"vendor\": \"HtmlUnit\", \"product\": \"htmlunit-neko\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 5.4.0\"}]}], \"references\": [{\"url\": \"https://github.com/HtmlUnit/htmlunit-neko/security/advisories/GHSA-39xg-prhf-8785\", \"name\": \"https://github.com/HtmlUnit/htmlunit-neko/security/advisories/GHSA-39xg-prhf-8785\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/HtmlUnit/htmlunit-neko/commit/c165891e0753aef3e05f5daa6250d3e8d4ada3c0\", \"name\": \"https://github.com/HtmlUnit/htmlunit-neko/commit/c165891e0753aef3e05f5daa6250d3e8d4ada3c0\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/HtmlUnit/htmlunit-neko/releases/tag/5.4.0\", \"name\": \"https://github.com/HtmlUnit/htmlunit-neko/releases/tag/5.4.0\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"HtmlUnit Neko is an HtmlUnit adaptation of NekoHTML. Prior to 5.4.0, HTMLWriterFilter writes decoded TEXTAREA and TITLE character content without entity encoding because both elements are treated as special content. During a parse-and-serialize round trip, entity references inside these escapable raw-text elements are decoded by the parser and then emitted as raw markup by printCharacters(), changing the document\u0027s semantics. Applications that use htmlunit-neko in an HTML sanitizer, content filter, or other parse-transform-serialize pipeline can therefore turn attacker-controlled encoded text into executable markup when the output is rendered by a browser. This issue is fixed in version 5.4.0.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-79\", \"description\": \"CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-10-15T18:39:13.508Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-104828\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-21T01:04:51.279Z\", \"dateReserved\": \"2026-10-02T14:17:09.335Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-10-15T18:36:49.613Z\", \"assignerShortName\": \"GitHub_M\"}",
      "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…