{"cve":"CVE-2020-5256","nvd":{"published":"2020-03-09T16:15:15.750","modified":"2026-06-17T03:21:08.630","status":"Modified","description":"BookStack before version 0.25.5 has a vulnerability where a user could upload PHP files through image upload functions, which would allow them to execute code on the host system remotely. They would then have the permissions of the PHP process. This most impacts scenarios where non-trusted users are given permission to upload images in any area of the application. The issue was addressed in a series of patches in versions 0.25.3, 0.25.4 and 0.25.5. Users should upgrade to at least v0.25.5 to avoid this vulnerability.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-434","CWE-95"],"references":["https://github.com/BookStackApp/BookStack/releases/tag/v0.25.3","https://github.com/BookStackApp/BookStack/releases/tag/v0.25.4","https://github.com/BookStackApp/BookStack/releases/tag/v0.25.5","https://github.com/BookStackApp/BookStack/security/advisories/GHSA-g9rq-x4fj-f5hx","https://github.com/BookStackApp/BookStack/releases/tag/v0.25.3"],"products":["bookstackapp:bookstack"],"source":"nvd","synced_at":"2026-10-19T21:02:53.949909883+00:00"},"epss":{"cve":"CVE-2020-5256","score":0.01969,"percentile":0.80399,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}