launch-editor: fs.existsSync() existence check can be bypassed on Windows

Exploitation

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

CVSS 4.0

7.5 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-112942: 1.34% estimated exploitation activity in the next 30 days; percentile 71.43 (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.

Summary launch-editor checked fs.existsSync(fileName) before passing a supplied path to an editor command. On Windows, an attacker can bypass this check with a crafted path ending in \\..:line:column. This removes the requirement that the attacker be able to place a file with a malicious filename. Combined with the % escaping issue described in GHSA-698v-4r3x-3vcv, this bypass can lead to OS command injection when an attacker controls the file argument. Impact Only apps that runs on Windows is affected. Details The earlier advisory assumed that fs.existsSync() required an attacker-controlled filename to exist. This advisory covers a bypass of that requirement. A crafted value ending in \\..:1:1 is interpreted differently by launch-editor-middleware, launch-editor, and Windows: 1. launch-editor-middleware calls path.resolve() while the final path component is ..:1:1, so it is not treated as a parent-directory component. 2. launch-editor treats :1:1 as a line-and-column suffix and…

Published by the source

20 Oct 2026, 19:48 UTC

Last modified by the source

20 Oct 2026, 20:00 UTC

Source last checked

26 Oct 2026, 13:07 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-587h-7wmj-h5pm

2. Revision 3 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-587h-7wmj-h5pm

4. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-587h-7wmj-h5pm

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# Patch Next advisory brief: CVE-2026-112942

Advisory: launch-editor: `fs.existsSync()` existence check can be bypassed on Windows
IDs: CVE-2026-112942, GHSA-587h-7wmj-h5pm
Record: https://patchnext.com/advisories/cve-2026-112942 (revision 4, source checked 26 Oct 2026, 13:07 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: vite 8.3.3, 8.2.4, 8.1.6, 7.3.7, 6.4.4; vite-plus 1.1.0; launch-editor 2.14.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm vite: affected >= 8.3.0, <= 8.3.2; >= 8.2.0, <= 8.2.3; >= 8.0.0, <= 8.1.5; >= 7.0.0, <= 7.3.6; <= 6.4.3; fixed in 7.3.7, 8.2.4, 8.1.6, 8.3.3, 6.4.4
- npm vite-plus: affected <= 1.0.0; fixed in 1.1.0
- npm launch-editor: affected <= 2.14.1; fixed in 2.14.2

## Suggested inspection (read-only)
- `npm ls vite --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls vite-plus --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls launch-editor --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 vite, vite-plus, launch-editor.
- 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-587h-7wmj-h5pm (GitHub-reviewed advisory GHSA-587h-7wmj-h5pm lists affected ranges: npm launch-editor >=0 =8.3.0 =8.2.0 =8.0.0 =7.0.0 =0 =0 <=1.0.0)
- Verified: https://osv.dev/vulnerability/GHSA-587h-7wmj-h5pm (OSV record GHSA-587h-7wmj-h5pm lists affected ranges: npm launch-editor >=0 =8.3.0 =8.2.0 =8.0.0 =7.0.0 =0 =0 <1.1.0 (fixed))

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