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

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

launch-editor allows users to open files with line numbers in editor from Node.js. Prior to 2.14.2, launch-editor-middleware processes an attacker-controlled Windows file argument where the file argument ends in a parent-directory component plus a line-and-column suffix: the path is resolved while the suffix is still present, and launch-editor removes the suffix before its existsSync check, leaving the existing parent directory for existsSync and allowing the attacker-controlled file argument to pass filename existence validation without requiring the malicious filename to exist. The bypass can lead to OS command injection when combined with the separately described Windows percent-expansion flaw. This issue is fixed in version 2.14.2.

Source published

20 Oct 2026 14:48:06 UTC

Source modified

21 Oct 2026 15:55:05 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

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

launch-editor allows users to open files with line numbers in editor from Node.js. Prior to 2.14.2, launch-editor-middleware processes an attacker-controlled Windows file argument where the file argument ends in a parent-directory component plus a line-and-column suffix: the path is resolved while the suffix is still present, and launch-editor removes the suffix before its existsSync check, leaving the existing parent directory for existsSync and allowing the attacker-controlled file argument to pass filename existence validation without requiring the malicious filename to exist. The bypass can lead to OS command injection when combined with the separately described Windows percent-expansion flaw. This issue is fixed in version 2.14.2.

Source published

Oct 20, 2026, 2:48:06 PM (timezone not stated)

Source modified

Oct 21, 2026, 3:55:05 PM (timezone not stated)

Observed here

7 Nov 2026 04:33:27 UTC

Source terms

ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD 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

launch-editor allows users to open files with line numbers in editor from Node.js. Prior to 2.14.2, launch-editor-middleware processes an attacker-controlled Windows file argument where the file argument ends in a parent-directory component plus a line-and-column suffix: the path is resolved while the suffix is still present, and launch-editor removes the suffix before its existsSync check, leaving the existing parent directory for existsSync and allowing the attacker-controlled file argument to pass filename existence validation without requiring the malicious filename to exist. The bypass can lead to OS command injection when combined with the separately described Windows percent-expansion flaw. This issue is fixed in version 2.14.2.

Source published

20 Oct 2026 15:17:17 UTC

Source modified

21 Oct 2026 16:17:15 UTC

Observed here

25 Oct 2026 05:17:13 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

### 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](https://github.com/vitejs/launch-editor/security/advisories/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 removes it, leaving a path ending in `\\..`. 3. On Windows, `fs.existsSync()` accepts the resulting path as the existing parent directory even though the attacker-controlled preceding component does not exist. 4. Because the existence check passes, the crafted filename reaches the Windows shell command.

Source published

20 Oct 2026 19:48:25 UTC

Source modified

20 Oct 2026 20:00:04 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · 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

Publisher rating · HIGH