{"schemaVersion":3,"id":"GHSA-P3F5-W63M-MXPH","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"Duplicate Advisory: webpack-dev-middleware vulnerable to Path Traversal via non-slash-terminated publicPath\n\n## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-g84c-rxfj-3j2c.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.","dates":{"published":"2026-08-24T15:31:51.000Z","modified":"2026-09-29T17:15:04.040Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":8.3,"severity":"high","version":"4.0","versionLabel":"v4.0","source":"OSV · Npm","vector":"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","computed":true,"selection":"version-preference"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"OSV · Npm","score":8.3,"severity":"high","vector":"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","exploitability":null,"impact":null,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Npm","score":7.4,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","exploitability":7.2,"impact":6.7,"computed":true}]},"epss":{"probability":null,"percentile":null,"severity":"unknown","asOf":null,"change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[],"last30":[]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[],"affected":[{"vendor":"Npm","product":"webpack-dev-middleware","name":"webpack-dev-middleware","label":"webpack-dev-middleware","ecosystem":"Npm","cpePart":null,"purl":"pkg:npm/webpack-dev-middleware","purlType":"npm","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-76844","label":"nvd.nist.gov/vuln/detail/CVE-2026-76844","hostname":"nvd.nist.gov","tags":["Advisory"]},{"url":"https://github.com/advisories/GHSA-wr3j-pwj9-hqq6","label":"github.com/advisories/GHSA-wr3j-pwj9-hqq6","hostname":"github.com","tags":["Advisory"]},{"url":"https://github.com/webpack/webpack-dev-middleware","label":"github.com/webpack/webpack-dev-middleware","hostname":"github.com","tags":["PACKAGE"]},{"url":"https://github.com/webpack/webpack-dev-middleware/blob/v8.1.1/src/middleware.js","label":"github.com/webpack/webpack-dev-middleware/blob/v8.1.1/src/middleware.js","hostname":"github.com","tags":["WEB"]},{"url":"https://www.vulncheck.com/advisories/webpack-dev-middleware-path-traversal-via-offset-slice-on-a-non-slash-terminated-publicpath","label":"www.vulncheck.com/advisories/…","hostname":"www.vulncheck.com","tags":["WEB"]}],"lineage":{"upstream":[],"downstream":["CVE-2026-76844"],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-08-24T15:31:51.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-09-29T17:15:04.040Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":33,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-21T21:22:43.014Z","stale":false,"partial":false}}