{"id":"CVE-2026-82450","summary":"BookStack before 26.05.4 Remote Code Execution via Book Cover","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.","modified":"2026-09-02T03:30:53.674857721Z","published":"2026-08-29T13:47:53.312Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82450.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-434"]},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/bookstackapp/bookstack","events":[{"introduced":"0"},{"fixed":"cec78b1bcf096a74bf0a79fae3f884dc1d0803e4"},{"fixed":"e210cc32e4cbb1efeae5c5c9d0fef8e3c6a752e6"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"26.05.4"}],"source":["DESCRIPTION","REFERENCES"]}}],"versions":["v26.05.3","v26.05.2","v26.05.1","v26.05","v26.03.5","v26.03.4","v26.03.3","v26.03.2","v26.03.1","v26.03","v25.12.9","v25.12.8","v25.12.7","v25.12.6","v25.12.5","v25.12.4","v25.12.3","v25.12.2","v25.12.1","v25.12","v25.11.6","v25.11.5","v25.11.4","v24.11.4","v25.11.3","v25.11.2","v25.11.1","v25.11","v25.07.3","v25.07.2","v25.07.1","v25.07","v25.05.2","v25.05.1","v25.05","v25.02.5","v25.02.4","v25.02.3","v25.02.2","v25.02.1","v25.02","v24.12.1","v24.12","v24.10.3","v24.10.2","v24.10.1","v24.10","v24.05.4","v24.05.3","v24.05.2","v24.05.1","v24.05","v24.02.3","v24.02.2","v24.02.1","v24.02","v23.12.3","v23.12.2","v23.12.1","v23.12","v23.10.4","v23.10.3","v23.10.2","v23.10.1","v23.10","v23.08.3","v23.08.2","v23.08.1","v23.08","v23.06.2","v23.06.1","v23.06","v23.05.2","v23.05.1","v23.05","v23.02.3","v23.02.2","v23.02.1","v23.02","v23.01.1","v23.01","v22.11.1","v22.11","v22.10.2","v22.10.1","v22.10","v22.09.1","v22.09","v22.07.3","v22.07.2","v22.07.1","v22.07","v22.06.2","v22.06.1","v22.06","v22.04.2","v22.04.1","v22.04","v22.03.1","v22.03","v22.02.3","v22.02.2","v22.02.1","v22.02","v21.12.5","v21.12.4","v21.12.3","v21.12.2","v21.12.1","v21.12","v21.11.3","v21.11.2","v21.11.1","v21.11","v21.10.3","v21.10.2","v21.10.1","v21.10","v21.08.6","v21.08.5","v21.08.4","v21.08.3","v21.08.2","v21.08.1","v21.08","v21.05.4","v21.05.3","v21.05.2","v21.05.1","v21.05","v21.04.6","v21.04.5","v21.04.4","v21.04.3","v21.04.2","v21.04.1","v21.04","v0.31.8","v0.31.7","v0.31.6","v0.31.5","v0.31.4","v0.31.3","v0.31.2","v0.31.1","v0.31.0","v0.30.7","v0.30.6","v0.30.5","v0.30.4","v0.30.3","v0.30.2","v0.30.1","v0.30.0","v0.29.3","v0.29.2","v0.29.1","v0.29.0","v0.28.3","v0.28.2","v0.28.1","v0.28.0","v0.27.5","v0.27.4","v0.27.3","v0.27.2","v0.27.1","v0.27","v0.26.4","v0.26.3","v0.26.2","v0.26.1","v0.26.0","v0.25.5","v0.25.4","v0.25.3","v0.25.2","v0.25.1","v0.25.0","v0.24.3","v0.24.2","v0.24.1","v0.24.0","v0.23.2","v0.23.1","v0.23.0","v0.22.0","v0.21.0","v0.20.3","v0.20.2","v0.20.1","v0.20.0","v0.19.0","v0.18.5","v0.18.4","v0.18.3","v0.18.2","v0.18.1","v0.18.0","v0.17.4","v0.17.3","v0.17.2","v0.17.1","v0.17.0","v0.16.3","v0.16.2","v0.16.1","v0.16.0","v0.15.3","v0.15.2","v0.15.1","v0.15.0","v0.14.3","v0.14.2","v0.14.1","v0.14.0","v0.13.1","v0.13.0","v0.12.2","v0.12.1","v0.12.0","v0.11.2","v0.11.1","v0.11.0","v0.10.0","v0.9.3","v0.9.2","v0.9.1","v0.9.0","v0.8.2","v0.8.1","v0.8.0","v0.7.6","v0.7.5","v0.7.4","v0.7.3","0.7.2","v.0.7.1","v0.7.0","v0.6.3","v0.6.2","v0.6.1","v0.6.0","v0.5.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-82450.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","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"}]}