CVE-2026-24909: @vltpkg/tar Vlt Mishandles Path Sanitization For Vulnerability

MODERATE
Advisory Identifier: GHSA-gf2c-jwcj-x929
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CVSS 5.9
CWE-23
Published
Advisory Summary

CVE-2026-24909 is a MODERATE (CVSS 5.9) vlt mishandles path sanitization for vulnerability (CWE-23: Relative Path Traversal) affecting @vltpkg/tar libraries in the npm ecosystem. The issue involves vlt mishandles path sanitization for tar. Remediation is available by upgrading affected packages to version 1.0.0-rc.10.

CVE-2026-24909 at a Glance

CVE Identifier CVE-2026-24909
GHSA Identifier GHSA-gf2c-jwcj-x929
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-23: Relative Path Traversal
Affected Product @vltpkg/tar
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N).

Attack Vector Local (AV:L)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-24909

To remediate this vulnerability, upgrade all affected @vltpkg/tar dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@vltpkg/tar fixed: 1.0.0-rc.10 
npm install @vltpkg/tar@1.0.0-rc.10
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls @vltpkg/tar

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-24909, inspect your project dependencies using npm:

npm ls @vltpkg/tar

Analyze the terminal output to locate any version of @vltpkg/tar in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.0-rc.10), your application is affected.

Note: The npm ls @vltpkg/tar command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-23: Relative Path Traversal, where the product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory. In @vltpkg/tar, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

vlt before 1.0.0-rc.10 mishandles path sanitization for tar, leading to path traversal during extraction.

CVE-2026-24909 Affected @vltpkg/tar Versions

1 component(s)
Fixed Versions:
1.0.0-rc.10
Product / Package Ecosystem Affected Versions Fixed Version
@vltpkg/tar
npm/@vltpkg/tar
npm
< 1.0.0-rc.10
1.0.0-rc.10

References

NVD — CVE-2026-24909 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-24909
@vltpkg/tar Source Repository REPOSITORY
https://github.com/vltpkg/vltpkg/pull/1334
Security Fix Commit FIX COMMIT
https://github.com/vltpkg/vltpkg/commit/ff8d4099a1929772cea2adf131285e90ede6b0dd
@vltpkg/tar Source Repository REPOSITORY
https://github.com/vltpkg/vltpkg
@vltpkg/tar Release RELEASE
https://github.com/vltpkg/vltpkg/releases/tag/v1.0.0-rc.10
www.koi.ai/blog/packagegate-6-... WEB
https://www.koi.ai/blog/packagegate-6-zero-days-in-js-package-managers-but-npm-wont-act
www.scworld.com/news/six-javascript... WEB
https://www.scworld.com/news/six-javascript-zero-day-bugs-lead-to-fears-of-supply-chain-attack

Frequently Asked Questions

What is CVE-2026-24909?
CVE-2026-24909 is a security vulnerability in @vltpkg/tar involving vlt Mishandles Path Sanitization for tar under CWE-23: Relative Path Traversal.
Which @vltpkg/tar versions are affected?
Affected versions include releases prior to 1.0.0-rc.10 across affected packages: @vltpkg/tar.
What version fixes CVE-2026-24909?
Upgrading to 1.0.0-rc.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @vltpkg/tar affected?
Yes, @vltpkg/tar is affected in releases prior to 1.0.0-rc.10. Upgrade your dependency to 1.0.0-rc.10 or later.
What is the CVSS score of CVE-2026-24909?
CVE-2026-24909 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N.
What CWE is associated with CVE-2026-24909?
CVE-2026-24909 is classified under CWE-23: Relative Path Traversal (The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory.).
How can I check npm dependencies for CVE-2026-24909?
Run the dependency tree command: 'npm ls @vltpkg/tar'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gf2c-jwcj-x929",
  "modified" : "2026-01-28T16:48:36Z",
  "published" : "2026-01-28T00:31:42Z",
  "aliases" : [ "CVE-2026-24909" ],
  "summary" : "vlt Mishandles Path Sanitization for tar",
  "details" : "vlt before 1.0.0-rc.10 mishandles path sanitization for tar, leading to path traversal during extraction.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@vltpkg/tar"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.0-rc.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-24909"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vltpkg/vltpkg/pull/1334"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vltpkg/vltpkg/commit/ff8d4099a1929772cea2adf131285e90ede6b0dd"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/vltpkg/vltpkg"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vltpkg/vltpkg/releases/tag/v1.0.0-rc.10"
  }, {
    "type" : "WEB",
    "url" : "https://www.koi.ai/blog/packagegate-6-zero-days-in-js-package-managers-but-npm-wont-act"
  }, {
    "type" : "WEB",
    "url" : "https://www.scworld.com/news/six-javascript-zero-day-bugs-lead-to-fears-of-supply-chain-attack"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-23" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-01-28T16:48:36Z",
    "nvd_published_at" : "2026-01-27T23:15:50Z"
  }
}