{"id":"CVE-2026-44593","summary":"esm.sh: Legacy Route Path Traversal Can Lead to RCE","details":"esm.sh is a no-build content delivery network (CDN) for web development. In 137 and earlier, the legacy router first retrieves a response from legacyServer, parses the incoming request path, and ultimately writes the data to storage via buildStorage.Put. The router concatenates the path components without sanitizing them, producing a storage key. When this key is used, the underlying file system resolves the relative segments and writes the file to the specified path. Thus an attacker can craft a request that writes data to arbitrary locations on the server.","aliases":["GHSA-3636-h3vx-6465","GO-2026-5071"],"modified":"2026-07-31T18:30:00.110955607Z","published":"2026-05-28T14:44:20.782Z","related":["openSUSE-SU-2026:21483-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44593.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-22"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44593.json"},{"type":"ADVISORY","url":"https://github.com/esm-dev/esm.sh/security/advisories/GHSA-3636-h3vx-6465"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44593"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/esm-dev/esm.sh","events":[{"introduced":"0"},{"last_affected":"2ff321d847219cf2c8152efeea3a20a72ee80f64"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"last_affected":"137"}]}}],"versions":["v137","v136_1","v136","v135_1","v135","v134","v133","v132","v131","v130","v129","v128","v127","v126","v125","v124","v123","v122","v121","v120","v119","v117","v116","v115","v114","v113","v112","v111","v110","v109","v108","v107","v106","v105","v104","v103","v102","v101","v100","v99","v98","v97","v96","v95","v94","v93","v92","v91","v90","v89","v88","v87","v86","v85","v84","v83","v82","v81","v80","v79","v78","v77","v76","v75","v74","v73","v72","v71","v70","v69","v68","v67","v66","v65","v64","v63","v62","v61","v60","v59","v57","v56","v55","v53","v52","v51","v50","v49","v47","v46","v45","v44","v43","v41","v40","v39","v38","v37","v35","v34"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44593.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"}]}