LibreChat's lack of JSON parsing error handling can lead to XSS

{
  "id": "243f5f7aaf6c0321d693ba3a97b89274a474624ae34d04722839cfce5c2eeb11",
  "url": "https://osv.dev/vulnerability/CVE-2025-66452",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "LibreChat's lack of JSON parsing error handling can lead to XSS",
    "summary": "LibreChat is a ChatGPT clone with additional features. In versions 0.8.0 and below, there is no handler for JSON parsing errors; SyntaxError from express.json() includes user input in the error message, which gets reflected in responses. User input (including HTML/JavaScript) can be exposed in error responses, creating an XSS risk if Content-Type isn't strictly enforced. This issue does not have a fix at the time of publication.",
    "evidence": "osv:CVE-2025-66452",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2025-66452",
      "aliases": [
        "CVE-2025-66452",
        "GHSA-q6c5-gvj5-c264"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/LibreChat-AI/LibreChat",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "b288d81f5a4625403bc880e93059d90d9aa51fe3"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.8.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.8.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.8.1",
            "chart-1.9.4",
            "v0.8.1-rc2",
            "chart-1.9.3",
            "v0.8.1-rc1",
            "chart-1.9.2",
            "v0.8.0",
            "chart-1.9.1",
            "v0.8.0-rc4",
            "chart-1.9.0",
            "v0.8.0-rc3",
            "v0.8.0-rc2",
            "v0.8.0-rc1",
            "v0.7.9",
            "librechat-1.8.9",
            "v0.7.9-rc1",
            "v0.7.8",
            "v0.7.8-rc1",
            "v0.7.7",
            "v0.7.7-rc1",
            "v0.7.6",
            "v0.7.6-rc1",
            "v0.7.5",
            "v0.7.5-rc2",
            "v0.7.5-rc1",
            "v0.7.4",
            "v0.7.4-rc1",
            "v0.7.3",
            "v0.7.3-rc2",
            "v0.7.3-rc",
            "v0.7.2",
            "v0.7.1",
            "v0.7.0",
            "v0.6.10",
            "v0.6.9",
            "v0.6.6",
            "v0.6.5",
            "v0.6.1",
            "v0.6.0",
            "v0.5.9",
            "v0.5.8",
            "v0.5.7",
            "v0.5.6",
            "v0.5.5",
            "v0.5.4",
            "v0.5.3",
            "v0.5.2",
            "v0.5.1",
            "v0.5.0",
            "v0.4.8",
            "v0.4.7",
            "v0.4.6",
            "v0.4.5",
            "v0.4.4",
            "v0.4.3",
            "v0.4.2",
            "v0.4.1",
            "v0.4.0",
            "v0.3.3",
            "v0.3.0",
            "v0.2.0",
            "v0.1.1",
            "v0.1.0",
            "v0.0.6",
            "v0.0.3",
            "v0.0.2",
            "v0.0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66452.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:46.191896283Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66452.json",
        "https://github.com/danny-avila/LibreChat/security/advisories/GHSA-q6c5-gvj5-c264",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-66452"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66452.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-66452",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 514172,
  "published_at": "2025-12-11T22:52:20.442+00:00"
}