DOMPurify before 3.4.0 ADD_TAGS Function Bypasses FORBID_TAGS

{
  "id": "04ef216d559a52529ff95eba384d8855a4c6729192b472ae0feb13d505e324ad",
  "url": "https://osv.dev/vulnerability/CVE-2026-65903",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DOMPurify before 3.4.0 ADD_TAGS Function Bypasses FORBID_TAGS",
    "summary": "DOMPurify before 3.4.0 contains a logic error in the ADD_TAGS function where short-circuit evaluation allows forbidden tags to bypass FORBID_TAGS restrictions. Attackers can craft input containing tags listed in FORBID_TAGS that are also added via ADD_TAGS function, causing them to be retained in sanitized output.",
    "evidence": "osv:CVE-2026-65903",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-65903",
      "aliases": [
        "CVE-2026-65903",
        "GHSA-39q2-94rc-95cp"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/cure53/dompurify",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "5b16e0b892e82b1779d62b9928b43c4c4ff290b9"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.4.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "cpe": "cpe:2.3:a:cure53:dompurify:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.4.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.3.3",
            "3.2.3",
            "3.1.3",
            "3.0.4",
            "2.4.3",
            "2.4.2",
            "2.4.1",
            "2.4.0",
            "2.3.12",
            "2.3.11",
            "2.3.10",
            "2.3.9",
            "2.3.8",
            "2.3.6",
            "2.3.5",
            "2.3.4",
            "2.3.3",
            "2.3.2",
            "2.3.1",
            "2.3.0",
            "2.2.9",
            "2.2.8",
            "2.2.7",
            "2.2.6",
            "2.2.4",
            "2.2.3",
            "2.2.2",
            "2.2.0",
            "2.1.1",
            "2.1.0",
            "2.0.17",
            "2.0.16",
            "2.0.15",
            "2.0.14",
            "2.0.13",
            "2.0.12",
            "2.0.11",
            "2.0.10",
            "2.0.9",
            "2.0.8",
            "2.0.6",
            "2.0.5",
            "2.0.4",
            "2.0.3",
            "2.0.2",
            "2.0.1",
            "2.0.0",
            "1.0.11",
            "1.0.10",
            "1.0.9",
            "1.0.8",
            "1.0.7",
            "1.0.6",
            "1.0.5",
            "1.0.4",
            "1.0.3",
            "1.0.2",
            "1.0.1",
            "1.0.0",
            "0.9.0",
            "0.8.9",
            "0.8.8",
            "0.8.7",
            "0.8.6",
            "0.8.5",
            "0.8.4",
            "0.8.3",
            "0.8.2",
            "0.8.1",
            "0.8.0",
            "0.7.3",
            "0.7.2",
            "0.7.1",
            "0.7.0",
            "0.6.7",
            "0.6.6",
            "0.6.5",
            "0.6.4",
            "0.6.3",
            "0.6.2",
            "0.6.1",
            "0.6.0",
            "0.4.5",
            "0.4.4",
            "0.4.3",
            "0.4.2",
            "0.4",
            "0.3",
            "v0.3",
            "0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-65903.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.119336824Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/65xxx/CVE-2026-65903.json",
        "https://github.com/cure53/DOMPurify/security/advisories/GHSA-39q2-94rc-95cp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-65903",
        "https://www.vulncheck.com/advisories/dompurify-before-add-tags-function-bypasses-forbid-tags"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-697"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/65xxx/CVE-2026-65903.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-65903",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 497229,
  "published_at": "2026-07-23T13:16:21.187+00:00"
}