Directory Traversal in serve

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2018-3712: 1.79% estimated exploitation activity in the next 30 days; percentile 78.39 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Affected versions of serve do not properly handle %2e (.) and %2f (/) characters, and allow the, characters to be used in paths. This can be used to traverse the directory tree and list content of any directory the user running the process has access to. Mitigating factors: This vulnerability only allows listing of directory contents and does not allow reading of arbitrary files. Recommendation Update to version 6.4.9 later.

Published by the source

27 Jul 2018, 17:07 UTC

Last modified by the source

8 Nov 2023, 04:00 UTC

Source last checked

26 Oct 2026, 12:22 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-q2qh-cgc2-qhr3

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-q2qh-cgc2-qhr3

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# Patch Next advisory brief: CVE-2018-3712

Advisory: Directory Traversal in serve
IDs: CVE-2018-3712, GHSA-q2qh-cgc2-qhr3
Record: https://patchnext.com/advisories/cve-2018-3712 (revision 2, source checked 26 Oct 2026, 12:22 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: serve 6.4.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm serve: affected <= 6.4.8; fixed in 6.4.9

## Suggested inspection (read-only)
- `npm ls serve --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on serve.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-q2qh-cgc2-qhr3 (OSV record GHSA-q2qh-cgc2-qhr3 lists affected ranges: npm serve >=0 <6.4.9 (fixed))
- Verified: https://github.com/advisories/GHSA-q2qh-cgc2-qhr3 (GitHub-reviewed advisory GHSA-q2qh-cgc2-qhr3 lists affected ranges: npm serve >=0 <=6.4.8)

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