{"action":"Upgrade winter/wn-backend-module to 1.2.13 or later.","affected":[{"fixed":"1.2.13","introduced":"0"}],"component":"winter/wn-backend-module","cve_ids":["CVE-2026-54256"],"ecosystem":"Packagist","epss":0.00239,"exploited":false,"fixed_versions":["1.2.13"],"ghsa_id":"GHSA-3277-h8g9-qj5f","id":"tcs_01M5KESESHHV54D4RFJ5XHES55","modified_at":"2026-08-20T18:48:08.338966Z","published_at":"2026-08-20T18:39:56Z","references":["https://osv.dev/vulnerability/GHSA-3277-h8g9-qj5f","https://github.com/wintercms/winter/security/advisories/GHSA-3277-h8g9-qj5f","https://github.com/wintercms/winter/security/advisories/GHSA-qq9m-vfv4-pj5w","https://github.com/wintercms/winter/commit/9cb0ae5f9d837db141ab111c6a7de8eed9603d25","https://github.com/wintercms/winter","https://github.com/wintercms/winter/releases/tag/v1.2.13"],"severity":{"label":"medium","score":5.4},"sources":[{"source":"osv","source_id":"GHSA-3277-h8g9-qj5f","url":"https://osv.dev/vulnerability/GHSA-3277-h8g9-qj5f"}],"summary":"Winter: Authenticated IDOR in backend FileUpload widget allows cross-user access to attachment metadata"}