{"id":"CVE-2026-82450","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-82450","summary":"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…","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.","published":"2026-08-29T14:16:37.930","modified":"2026-08-29T14:16:37.930","cvss":{"score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":{"url":"https://github.com/BookStackApp/BookStack/commit/e210cc32e4cbb1efeae5c5c9d0fef8e3c6a752e6","label":"BookStackApp/BookStack@e210cc3"},"references":[{"type":"WEB","url":"https://github.com/BookStackApp/BookStack"},{"type":"WEB","url":"https://github.com/BookStackApp/BookStack/commit/e210cc32e4cbb1efeae5c5c9d0fef8e3c6a752e6"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/bookstack-before-26.05.4-remote-code-execution-via-book-cover"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-08-29T14:16:37.930"}}