Lightpanda: fetch() and XMLHttpRequest attach session cookies to cross-origin requests regardless of credentials mode

{
  "id": "3f7a4b49e35fd6f983809cbb0d4aea25d88f322ec92c6678aed8db230ffa197f",
  "url": "https://osv.dev/vulnerability/CVE-2026-52843",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Lightpanda: fetch() and XMLHttpRequest attach session cookies to cross-origin requests regardless of credentials mode",
    "summary": "Lightpanda is a headless browser designed for AI and automation. Prior to 0.2.9, Lightpanda fetch() and XMLHttpRequest unconditionally attached session cookies to every HTTP request, ignoring credentials: omit, credentials: same-origin, credentials: include, and XMLHttpRequest.withCredentials, allowing an attacker-controlled origin in a Lightpanda session to issue authenticated cross-origin requests against a victim origin. This issue is fixed in version 0.2.9.",
    "evidence": "osv:CVE-2026-52843",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-52843",
      "aliases": [
        "CVE-2026-52843",
        "GHSA-36mm-v3c2-24cc"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/lightpanda-io/browser",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "b2b1302fa2638bcc295c6ad0d9a71bf9aa75adb1"
                },
                {
                  "fixed": "2cdaac780bed65db98bbb6ed2ad5bc6011863c76"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.2.9"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "2cdaac780bed65db98bbb6ed2ad5bc6011863c76"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "b2b1302fa2638bcc295c6ad0d9a71bf9aa75adb1"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "0.2.9"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.2.8",
            "0.2.7",
            "v0.2.6",
            "v0.2.5",
            "v0.2.4",
            "v0.2.3",
            "v0.2.2",
            "v0.2.1",
            "v0.2.0",
            "beta",
            "nightly",
            "alpha"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52843.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.526352115Z",
      "provider": "osv",
      "references": [
        "https://github.com/lightpanda-io/browser/releases/tag/0.2.9",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52843.json",
        "https://github.com/lightpanda-io/browser/security/advisories/GHSA-36mm-v3c2-24cc",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-52843",
        "https://github.com/lightpanda-io/browser/commit/2cdaac780bed65db98bbb6ed2ad5bc6011863c76",
        "https://github.com/lightpanda-io/browser/pull/2155"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-346"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52843.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-52843",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 496410,
  "published_at": "2026-07-15T16:16:07.762+00:00"
}