A AegiFlow
HIGHCVSS 8.3

GHSA-p3f5-w63m-mxph

Duplicate Advisory: webpack-dev-middleware vulnerable to Path Traversal via non-slash-terminated publicPath

Published
2026-08-24
Modified
2026-09-29
Sources
github-advisory

Summary

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-g84c-rxfj-3j2c. This link is maintained to preserve external references. ## Original Description webpack-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.

Affected packages

EcosystemPackageAffected versionsFixed versions
npmwebpack-dev-middleware——

Remediation: No patched version is listed by GitHub.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.