{"id":"GHSA-p3f5-w63m-mxph","summary":"Duplicate Advisory: webpack-dev-middleware vulnerable to Path Traversal via non-slash-terminated publicPath","details":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-g84c-rxfj-3j2c. This link is maintained to preserve external references.\n\n## Original Description\nwebpack-dev-middleware resolves a request to a local file in getFilenameFromUrl by testing the request pathname against a traversal guard and then slicing it at a fixed character offset. The guard, UP_PATH_REGEXP applied to path.normalize(`./${pathname}`), only matches \"..\" that stands as a whole path segment, while the containment test is the string comparison pathname.startsWith(publicPathPathname) and the file path is built as path.join(outputPath, pathname.slice(publicPathPathname.length)). When the configured publicPath has no trailing slash, a request such as GET /assets../.env against publicPath /assets yields the pathname /assets../.env, whose only dot-dot sits inside the segment \"assets..\" and so passes the guard, but the offset slice cuts within that segment and hands \"../.env\" to path.join, resolving one directory above outputPath. Reading a file from that path requires the middleware to be backed by the physical filesystem, which happens when writeToDisk is true or a custom outputFileSystem is supplied, since the default memfs volume holds only build output. Traversal depth is limited to a single directory because a separately delimited dot-dot segment is collapsed during URL parsing before the guard runs. The default publicPath value of \"auto\" resolves to \"/\" and is not affected. This is an incomplete fix for CVE-2024-29180: the guard and offset slice were introduced by that fix and are present in every release from 5.3.4, 6.1.2 and 7.1.0 onward.","modified":"2026-09-29T17:15:04.040950257Z","published":"2026-08-24T15:31:51Z","withdrawn":"2026-09-29T16:59:08Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-09-29T16:59:08Z","nvd_published_at":"2026-08-24T14:17:02Z","cwe_ids":["CWE-22"],"severity":"HIGH"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-76844"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-wr3j-pwj9-hqq6"},{"type":"PACKAGE","url":"https://github.com/webpack/webpack-dev-middleware"},{"type":"WEB","url":"https://github.com/webpack/webpack-dev-middleware/blob/v8.1.1/src/middleware.js"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/webpack-dev-middleware-path-traversal-via-offset-slice-on-a-non-slash-terminated-publicpath"}],"affected":[{"package":{"name":"webpack-dev-middleware","ecosystem":"npm","purl":"pkg:npm/webpack-dev-middleware"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-p3f5-w63m-mxph/GHSA-p3f5-w63m-mxph.json","last_known_affected_version_range":"\u003c 7.4.5"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}