crawl4ai before 0.9.3 DOM-based XSS via Playground UI

{
  "id": "61a8c7b1638ea2cc50b2f7d3f0f43852c666c582b0105c6753a58f4ceec8377f",
  "url": "https://osv.dev/vulnerability/CVE-2026-91944",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "crawl4ai before 0.9.3 DOM-based XSS via Playground UI",
    "summary": "crawl4ai versions before 0.9.3 contain a DOM-based cross-site scripting vulnerability in the Playground UI where the forceHighlightElement() function assigns textContent back to innerHTML, re-parsing JSON responses as HTML. Attackers can inject malicious scripts through crawled page content like the page title to steal the operator's API token from sessionStorage and gain full server control.",
    "evidence": "osv:CVE-2026-91944",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-91944",
      "aliases": [
        "CVE-2026-91944",
        "GHSA-m446-hp3q-qfxp"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/unclecode/crawl4ai",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4bcd5fa8a56000ce103dd499e8ecdff2439f3e9c"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.9.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.9.3"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.9.2",
            "docker-rebuild-v0.9.2",
            "v0.9.1",
            "docker-rebuild-v0.9.1",
            "v0.9.0",
            "docker-rebuild-v0.9.0",
            "v0.8.9",
            "docker-rebuild-v0.8.9",
            "v0.8.8",
            "docker-rebuild-v0.8.8",
            "v0.8.7",
            "docker-rebuild-v0.8.7",
            "docker-rebuild-v0.8.6",
            "v0.8.6",
            "v0.7.4",
            "v0.7.3",
            "v0.7.2",
            "v0.7.1",
            "v0.7.0",
            "vr0.6.3",
            "v0.6.3",
            "vr0.6.0",
            "vr0.6.0rc1",
            "v0.5.0.post1",
            "v0.4.243",
            "v0.4.24",
            "v0.3.745",
            "v.3.72",
            "v0.3.6",
            "0.3.4",
            "v0.3.3",
            "v0.3.0",
            "v0.2.77",
            "v0.0.75",
            "v0.2.74",
            "v0.2.73",
            "v0.2.72",
            "v0.2.71",
            "v0.2.7",
            "v0.2.6",
            "v0.2.4",
            "v0.2.1",
            "v0.2.0",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-91944.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.355808971Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91944.json",
        "https://github.com/unclecode/crawl4ai/security/advisories/GHSA-m446-hp3q-qfxp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-91944",
        "https://www.vulncheck.com/advisories/crawl4ai-before-0.9.3-dom-based-xss-via-playground-ui"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91944.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-91944",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489653,
  "published_at": "2026-09-15T15:18:03.786+00:00"
}