Vulnerability-Lookup

GHSA-J8R4-32C5-33RC

Vulnerability from github – Published: 2026-09-24 19:33 – Updated: 2026-09-24 19:33

Summary

xhtml-purifier has HTML attribute-injection (sanitizer bypass) that leads to XSS

Details

xhtml-purifier does not HTML-entity-encode attribute values when serializing its sanitized output. In attributeString() (XHTMLPurifier.js, around line 148) the attribute value is concatenated directly into a double-quoted attribute without encoding. As a result, an attacker-controlled value in any allowed attribute (class, style, title, alt, src, href) can include a double-quote character to break out of the attribute and inject an additional attribute, such as a JavaScript event handler (for example onmouseover or onerror). The injected handler survives sanitization and executes when the output is rendered, which is a sanitizer bypass leading to cross-site scripting. The fix HTML-entity-encodes attribute values before serialization.

Severity

6.1 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.4.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "xhtml-purifier"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.4.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-61784"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-24T19:33:23Z",
    "nvd_published_at": "2026-09-24T18:17:16Z",
    "severity": "MODERATE"
  },
  "details": "xhtml-purifier does not HTML-entity-encode attribute values when serializing its sanitized output. In attributeString() (XHTMLPurifier.js, around line 148) the attribute value is concatenated directly into a double-quoted attribute without encoding. As a result, an attacker-controlled value in any allowed attribute (class, style, title, alt, src, href) can include a double-quote character to break out of the attribute and inject an additional attribute, such as a JavaScript event handler (for example onmouseover or onerror). The injected handler survives sanitization and executes when the output is rendered, which is a sanitizer bypass leading to cross-site scripting. The fix HTML-entity-encodes attribute values before serialization.",
  "id": "GHSA-j8r4-32c5-33rc",
  "modified": "2026-09-24T19:33:24Z",
  "published": "2026-09-24T19:33:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/cstigler/node-xhtml-purifier/security/advisories/GHSA-j8r4-32c5-33rc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-61784"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cstigler/node-xhtml-purifier/pull/6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cstigler/node-xhtml-purifier/commit/21d461ad23e7bc9b3073693d5b51b9b8662044d3"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/cstigler/node-xhtml-purifier"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cstigler/node-xhtml-purifier/releases/tag/v0.4.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "xhtml-purifier has HTML attribute-injection (sanitizer bypass) that leads to XSS"
}

CVE-2026-61784 (GCVE-0-2026-61784)

Vulnerability from cvelistv5 – Published: 2026-09-24 17:35 – Updated: 2026-09-24 18:03

Title

xhtml-purifier has HTML attribute-injection (sanitizer bypass) that leads to XSS

Summary

xhtml-purifier is a Node.js library to take in raw/unknown/untrusted HTML and output cleaned, purified, trusted HTML. Versions prior to 0.4.3 do not HTML-entity-encode attribute values when serializing its sanitized output. In attributeString() (XHTMLPurifier.js, around line 148) the attribute value is concatenated directly into a double-quoted attribute without encoding. As a result, an attacker-controlled value in any allowed attribute (class, style, title, alt, src, href) can include a double-quote character to break out of the attribute and inject an additional attribute, such as a JavaScript event handler (for example onmouseover or onerror). The injected handler survives sanitization and executes when the output is rendered, which is a sanitizer bypass leading to cross-site scripting. The fix in version 0.4.3 HTML-entity-encodes attribute values before serialization.

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 · CISA-ADP (v2.0.3)

Decision recorded 2026-09-24 18:02 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-116 - Improper Encoding or Escaping of Output

Assigner

GitHub_M mitre root Scorecard

References

2 references

URL	Tags
https://github.com/cstigler/node-xhtml-purifier/s…	x_refsource_CONFIRM
https://github.com/cstigler/node-xhtml-purifier/c…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
cstigler	node-xhtml-purifier	Affected: < 0.4.3

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-61784",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-24T18:02:51.787487Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-24T18:03:05.576Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "node-xhtml-purifier",
          "vendor": "cstigler",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.4.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "xhtml-purifier is a Node.js library to take in raw/unknown/untrusted HTML and output cleaned, purified, trusted HTML. Versions prior to 0.4.3 do not HTML-entity-encode attribute values when serializing its sanitized output. In attributeString() (XHTMLPurifier.js, around line 148) the attribute value is concatenated directly into a double-quoted attribute without encoding. As a result, an attacker-controlled value in any allowed attribute (class, style, title, alt, src, href) can include a double-quote character to break out of the attribute and inject an additional attribute, such as a JavaScript event handler (for example onmouseover or onerror). The injected handler survives sanitization and executes when the output is rendered, which is a sanitizer bypass leading to cross-site scripting. The fix in version 0.4.3 HTML-entity-encodes attribute values before serialization."
        }
      ],
      "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"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-116",
              "description": "CWE-116: Improper Encoding or Escaping of Output",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-24T17:35:57.096Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/cstigler/node-xhtml-purifier/security/advisories/GHSA-j8r4-32c5-33rc",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/cstigler/node-xhtml-purifier/security/advisories/GHSA-j8r4-32c5-33rc"
        },
        {
          "name": "https://github.com/cstigler/node-xhtml-purifier/commit/21d461ad23e7bc9b3073693d5b51b9b8662044d3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/cstigler/node-xhtml-purifier/commit/21d461ad23e7bc9b3073693d5b51b9b8662044d3"
        }
      ],
      "source": {
        "advisory": "GHSA-j8r4-32c5-33rc",
        "discovery": "UNKNOWN"
      },
      "title": "xhtml-purifier has HTML attribute-injection (sanitizer bypass) that leads to XSS"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-61784",
    "datePublished": "2026-09-24T17:35:57.096Z",
    "dateReserved": "2026-07-10T20:06:05.616Z",
    "dateUpdated": "2026-09-24T18:03:05.576Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-J8R4-32C5-33RC

CVE-2026-61784 (GCVE-0-2026-61784)

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