Disclosure summary
> [!IMPORTANT] > CVE-2026-76844 was assigned and published for this issue by VulnCheck on 2026-08-24 without prior coordination with the webpack maintainers or the OpenJS Foundation, which holds the CVE Numbering Authority scope for webpack projects. Neither the maintainers nor the OpenJS CNA were notified before publication, and no fix was available at that time. This advisory is the coordinated record produced by the webpack maintainers and the OpenJS Foundation CNA. ### Impact `webpack-dev-middleware` resolves a request to a local file in `getFilenameFromUrl`. When the configured `publicPath` has no trailing slash (for example `/assets`), a request that shares that prefix without being under it (for example `/assets../secret`) still passes the containment check, and the `..` guard does not catch it because it runs on the path before the `publicPath` prefix is stripped. The stripped remainder then escapes the configured output directory once joined, so an unauthenticated request can read files outside the output root. Applications serving `webpack-dev-middleware` (directly or via `webpack-dev-server`) with a `publicPath` that does not end in a slash are affected. A development se
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
GitHub Reviewed Security Advisories · GHSA-g84c-rxfj-3j2c
Open original source · Updated Sep 29, 2026
webpack-dev-middleware vulnerable to Path Traversal via non-slash-terminated publicPath
Source severity: HIGH / 0
| Ecosystem | Package | Affected range | First patched |
|---|---|---|---|
| npm | webpack-dev-middleware | >= 8.0.0, < 8.3.0 | 8.3.0 |
| npm | webpack-dev-middleware | < 7.4.5 | 7.4.6 |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Reviewed advisory
PUBLISHED 2026-09-29T12:59:18-04:00
MODIFIED 2026-09-29T12:59:19-04:00
INGESTED 2026-10-06T11:43:08-04:00