moment vulnerable to Path Traversal via crafted non-string locale name

Exploitation

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

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS

• CVE-2026-17495: 0.52% estimated exploitation activity in the next 30 days; percentile 44.19 (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.

Impact moment before 2.31.0 is vulnerable to path traversal in moment.locale(). When an application passes a non-string, attacker-influenced value to moment.locale(), a specially crafted object can bypass the locale name validation and cause moment to load a file from an attacker-controlled path. This is a further bypass of the validation added in 2.29.2 for CVE-2022-24785. This affects server-side (npm) users only. Plain string input is not affected: the existing validation correctly rejects strings that contain path separators. Patches This issue is patched in moment 2.31.0. Workarounds Validate that any user-supplied input is a string before passing it to moment.locale().

Published by the source

29 Sep 2026, 23:46 UTC

Last modified by the source

30 Sep 2026, 00:00 UTC

Source last checked

26 Oct 2026, 13:06 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-4p3w-j4w9-5jqw

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-4p3w-j4w9-5jqw

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-4p3w-j4w9-5jqw

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# Patch Next advisory brief: CVE-2026-17495

Advisory: moment vulnerable to Path Traversal via crafted non-string locale name
IDs: CVE-2026-17495, GHSA-4p3w-j4w9-5jqw
Record: https://patchnext.com/advisories/cve-2026-17495 (revision 3, source checked 26 Oct 2026, 13:06 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: moment 2.31.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm moment: affected >= 2.29.2, < 2.31.0; fixed in 2.31.0

## Suggested inspection (read-only)
- `npm ls moment --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 moment.
- 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://github.com/advisories/GHSA-4p3w-j4w9-5jqw (GitHub-reviewed advisory GHSA-4p3w-j4w9-5jqw lists affected ranges: npm moment >=2.29.2 <2.31.0)
- Verified: https://osv.dev/vulnerability/GHSA-4p3w-j4w9-5jqw (OSV record GHSA-4p3w-j4w9-5jqw lists affected ranges: npm moment >=2.29.2 <2.31.0 (fixed))

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