{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "26.05.4"
              }
            ],
            "source": [
              "DESCRIPTION",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "cec78b1bcf096a74bf0a79fae3f884dc1d0803e4"
            },
            {
              "fixed": "e210cc32e4cbb1efeae5c5c9d0fef8e3c6a752e6"
            }
          ],
          "repo": "https://github.com/bookstackapp/bookstack",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-434"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82450.json"
  },
  "details": "BookStack before 26.05.4 contains a remote code execution vulnerability in the portable ZIP import functionality that allows users with Import Content and Create Books permissions to upload a PHP polyglot file as a book cover. Attackers can bypass image extension validation by embedding a PHP file with a .php filename in the ZIP archive, which is stored in the public web root and executed by unauthenticated requests.",
  "id": "CVE-2026-82450",
  "modified": "2026-09-02T03:30:53.674857721Z",
  "published": "2026-08-29T13:47:53.312Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82450.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-82450"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/bookstack-before-26.05.4-remote-code-execution-via-book-cover"
    },
    {
      "type": "FIX",
      "url": "https://github.com/BookStackApp/BookStack/commit/e210cc32e4cbb1efeae5c5c9d0fef8e3c6a752e6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/BookStackApp/BookStack"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "BookStack before 26.05.4 Remote Code Execution via Book Cover"
}