{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.3.0"
              },
              {
                "last_affected": "0.4.8"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "4795dc006f2c820bb11f3e9b5256017830f274db"
            },
            {
              "last_affected": "a5e8b2d5977fedc167e1efb03a4f80121da4842e"
            }
          ],
          "repo": "https://github.com/sdelements/lets-chat",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-862"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66750.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "55e8833974c83559ed2cbc12bc15febeb2466254"
          },
          {
            "last_affected": "617207ff3c0c0bf8e3c7a915bd9ec03f1dd8390c"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Let's Chat 0.3.0 through 0.4.8 contains a broken access control vulnerability that allows authenticated attackers to download file attachments from private and password-protected rooms they are not a member of by exploiting missing room membership checks in the file retrieval route. Attackers can enumerate adjacent MongoDB ObjectIds derived from a known file ID to recover files uploaded by other users, as the GET /files/:id/:name route in app/controllers/files.js only enforces login authentication without consulting room membership or the Room.canJoin check.",
  "id": "CVE-2026-66750",
  "modified": "2026-08-01T03:32:58.794502272Z",
  "published": "2026-07-28T15:33:04.344Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66750.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-66750"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/let-s-chat-broken-access-control-file-disclosure-via-get-files-route"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/sdelements/lets-chat"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/theopaid/Insufficient-Access-Controls-Allow-for-Unauthorized-File-Downloads-Let-s-Chat-"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Let's Chat 0.3.0 - 0.4.8 Broken Access Control File Disclosure via GET /files route"
}