{"id":"CVE-2026-90871","kind":"vulnerability","aliases":["CVE-2026-90871"],"related":[],"title":"WS_FTP Server: path traversal lets unauthenticated users reach files outside directory","description":"Improper limitation of a pathname to a restricted directory in Progress Software WS_FTP Server versions prior to 2024.0.7 and 2025.0.4 on Windows could allow an unauthenticated attacker to affect files outside the intended directory.","summary":"WS_FTP Server on Windows fails to keep file paths inside their intended directory. An unauthenticated attacker can affect files outside that directory.","severity":"medium","cvss":5.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["file-transfer","runtime","windows","ws_ftp_server"],"not_affected_if":["non-windows-hosts","patched-versions"],"how_to_check":"- Check the installed WS_FTP Server version against the fixed versions below.\n- Confirm whether the server runs on Windows.","fix":"- WS_FTP Server `2024.0.7` or later on the 2024 line\n- WS_FTP Server `2025.0.4` or later on the 2025 line","status":"open","published_at":"2026-10-29T16:20:05+00:00","first_seen_at":"2026-10-29T16:26:03+00:00","triaged_at":"2026-10-29T16:31:46+00:00","updated_at":"2026-10-29T16:31:46+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-10-29T16:31:46Z","model":"claude-haiku-5-5","output":{"fix":"- WS_FTP Server `2024.0.7` or later on the 2024 line\n- WS_FTP Server `2025.0.4` or later on the 2025 line","reach":"network","title":"WS_FTP Server: path traversal lets unauthenticated users reach files outside directory","impact":"medium","summary":"WS_FTP Server on Windows fails to keep file paths inside their intended directory. An unauthenticated attacker can affect files outside that directory.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["ws_ftp_server","windows","file-transfer"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"unauthenticated attacker affects files outside the intended directory","analyst_note":"","how_to_check":"- Check the installed WS_FTP Server version against the fixed versions below.\n- Confirm whether the server runs on Windows.","plain_action":"","needs_analyst":false,"not_affected_if":["non-windows-hosts","patched-versions"],"who_is_affected":"WS_FTP Server installations on Windows older than 2024.0.7 or 2025.0.4 are in scope. The sources do not describe any non-default configuration that is required.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000642,"input_tokens":4109,"output_tokens":463,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':14A,17A '-90871':15A,18A '2024.0.7':68C '2025.0.4':70C 'affect':45B,79C 'allow':74C 'attack':43B,77C 'could':73C 'cve':13A,16A 'directori':12A,40B,49B,58C,84C 'fail':32B 'file':10A,20B,35B,46B,80C 'file-transf':19B 'ftp':2A,25B,28B,63C 'improp':50C 'insid':37B 'intend':39B,83C 'keep':34B 'let':6A 'limit':51C 'outsid':11A,47B,81C 'path':4A,36B 'pathnam':54C 'prior':66C 'progress':60C 'reach':9A 'restrict':57C 'runtim':22B 'server':3A,26B,29B,64C 'softwar':61C 'transfer':21B 'travers':5A 'unauthent':7A,42B,76C 'user':8A 'version':65C 'window':23B,31B,72C 'ws':1A,24B,27B,62C","nicknames":[],"mitigations":[],"who_affected":"WS_FTP Server installations on Windows older than 2024.0.7 or 2025.0.4 are in scope. The sources do not describe any non-default configuration that is required.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"first_public_at":"2026-10-29T16:20:05+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","cvss_by":"security@progress.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-90871","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90871","severity":null,"published_at":"2026-10-29T16:20:05+00:00","modified_at":"2026-10-29T16:24:53+00:00","first_seen_at":"2026-10-29T16:26:03+00:00","fetched_at":"2026-10-29T16:26:03+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}