{"id":"CVE-2026-40611","revision":"0fa821a61df9484a9e524f35373d9512","records":[{"revision":"0fa821a61df9484a9e524f35373d9512","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-40611","aliases":[],"title":"Lego: Arbitrary File Write via Path Traversal in Webroot HTTP-01 Provider","description":"Let's Encrypt client and ACME library written in Go (Lego). Prior to 4.34.0, the webroot HTTP-01 challenge provider in lego is vulnerable to arbitrary file write and deletion via path traversal. A malicious ACME server can supply a crafted challenge token containing ../ sequences, causing lego to write attacker-influenced content to any path writable by the lego process. This vulnerability is fixed in 4.34.0.","state":0,"publishedAt":"2026-04-21T17:58:35.221+00:00","modifiedAt":"2026-07-15T01:00:42.598+00:00","affected":[{"ecosystem":"Vendor product","name":"lego","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"go-acme\",\n                    \"product\": \"lego\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 4.34.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://github.com/go-acme/lego/security/advisories/GHSA-qqx8-2xmm-jrv8"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-40611","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-40611","identifiers":["CVE-2026-40611"]},"retained":false,"historicalAffected":[]}],"coverage":[]}