GHSA-g84c-rxfj-3j2c

Source

https://github.com/advisories/GHSA-g84c-rxfj-3j2c

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-g84c-rxfj-3j2c/GHSA-g84c-rxfj-3j2c.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-g84c-rxfj-3j2c

Aliases

Published

2026-09-29T16:59:18Z

Modified

2026-09-29T17:25:42Z

Severity

7.4 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N CVSS Calculator

Summary

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

Details

[!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 server reachable on the network can be attacked with a single request and no victim interaction.

Patches

Patched in webpack-dev-middleware 8.3.0. There is no backport to the 5.x, 6.x, or 7.x lines; users on those lines should upgrade to 8.3.0 or later.

Workarounds

Configure publicPath with a trailing slash (for example /assets/ instead of /assets), or upgrade to a patched version.

References

CVE-2024-29180 (GHSA-wr3j-pwj9-hqq6), the earlier path traversal in the same component that this issue bypasses.

Database specific

{
    "cwe_ids":  [
        "CWE-22"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-09-29T16:59:18Z",
    "nvd_published_at":  null,
    "severity":  "HIGH"
}

References

Affected packages

npm / webpack-dev-middleware

Package

Name: webpack-dev-middleware; View open source insights on deps.dev
Purl: pkg:npm/webpack-dev-middleware

Affected ranges

Type: SEMVER
Events: Introduced

8.0.0

Fixed

8.3.0

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-g84c-rxfj-3j2c/GHSA-g84c-rxfj-3j2c.json"

npm / webpack-dev-middleware

Package

Name: webpack-dev-middleware; View open source insights on deps.dev
Purl: pkg:npm/webpack-dev-middleware

Affected ranges

Type: SEMVER
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

7.4.6

Database specific

last_known_affected_version_range

"< 7.4.5"

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-g84c-rxfj-3j2c/GHSA-g84c-rxfj-3j2c.json"