CVE-2026-14620: Webpack dev server Webpack-dev-server Vulnerable To Cross-site Request Vulnerability

MODERATE
Advisory Identifier: GHSA-f5vj-f2hx-8m93
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CVSS 4.7
CWE-749 CWE-352
Published
Advisory Summary

CVE-2026-14620 is a MODERATE (CVSS 4.7) webpack-dev-server vulnerable to cross-site request vulnerability (CWE-749: Exposed Dangerous Method or Function) affecting Webpack dev server libraries in the npm ecosystem. The issue involves webpack-dev-server vulnerable to cross-site request forgery via internal developer endpoints. Remediation is available by upgrading affected packages to version 5.2.6.

CVE-2026-14620 at a Glance

CVE Identifier CVE-2026-14620
GHSA Identifier GHSA-f5vj-f2hx-8m93
Severity MODERATE
CVSS v3.1 Base Score 4.7
CWE Classification CWE-749: Exposed Dangerous Method or Function
Affected Product Webpack dev server
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 4.7

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

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

How to Fix CVE-2026-14620

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

webpack-dev-server fixed: 5.2.6 
npm install webpack-dev-server@5.2.6
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 webpack-dev-server

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-14620, inspect your project dependencies using npm:

npm ls webpack-dev-server

Analyze the terminal output to locate any version of Webpack dev server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.2.6), your application is affected.

Note: The npm ls webpack-dev-server 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-749: Exposed Dangerous Method or Function, where the product provides an applications programming interface (api) or similar interface for interaction with external actors, but the interface includes a dangerous method or function that is not properly restricted. In Webpack dev server, 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

### Impact The internal `/webpack-dev-server/open-editor` and `/webpack-dev-server/invalidate` endpoints perform state-changing actions on any `GET` request, without verifying that the request originated from the dev server's own page. Any website a developer visits while the dev server is running can trigger them cross-origin with no interaction beyond the visit. An attacker can open an arbitrary existing local file in the developer's editor, including files outside the project root (e.g. `~/.ssh/config`). The file's contents are not returned to the attacker. Repeated requests can also spawn editor processes and force recompilations, degrading the developer's machine. ### Patches Fixed in `webpack-dev-server` 5.2.6 by rejecting cross-site requests to the `/webpack-dev-server/open-editor` and `/webpack-dev-server/invalidate` endpoints (see [PR #5698](https://github.com/webpack/webpack-dev-server/pull/5698)). ### Workarounds None

CVE-2026-14620 Affected Webpack dev server Versions

1 component(s)
Fixed Versions:
5.2.6
Product / Package Ecosystem Affected Versions Fixed Version
webpack-dev-server
npm/webpack-dev-server
npm
< 5.2.6
5.2.6

References

GitHub Advisory / Wiki ADVISORY
https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-f5vj-f2hx-8m93
NVD — CVE-2026-14620 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-14620
Webpack dev server Source Repository REPOSITORY
https://github.com/webpack/webpack-dev-server/pull/5698
Security Fix Commit FIX COMMIT
https://github.com/webpack/webpack-dev-server/commit/80cd9eea54975fe632a518d8bd902a260f374e7c
Webpack dev server Security Information SECURITY
https://cna.openjsf.org/security-advisories.html
Webpack dev server Source Repository REPOSITORY
https://github.com/webpack/webpack-dev-server
Webpack dev server Release RELEASE
https://github.com/webpack/webpack-dev-server/releases/tag/v5.2.6

Frequently Asked Questions

What is CVE-2026-14620?
CVE-2026-14620 is a security vulnerability in Webpack dev server involving webpack-dev-server vulnerable to cross-site request forgery via internal developer endpoints under CWE-749: Exposed Dangerous Method or Function.
Which Webpack dev server versions are affected?
Affected versions include releases prior to 5.2.6 across affected packages: webpack-dev-server.
What version fixes CVE-2026-14620?
Upgrading to 5.2.6 (or the latest patched release for your respective branch) resolves the vulnerability.
Is webpack-dev-server affected?
Yes, webpack-dev-server is affected in releases prior to 5.2.6. Upgrade your dependency to 5.2.6 or later.
What is the CVSS score of CVE-2026-14620?
CVE-2026-14620 has a CVSS v3.1 base score of 4.7 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:L.
What CWE is associated with CVE-2026-14620?
CVE-2026-14620 is classified under CWE-749: Exposed Dangerous Method or Function (The product provides an Applications Programming Interface (API) or similar interface for interaction with external actors, but the interface includes a dangerous method or function that is not properly restricted.).
How can I check npm dependencies for CVE-2026-14620?
Run the dependency tree command: 'npm ls webpack-dev-server'. 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-f5vj-f2hx-8m93",
  "modified" : "2026-07-20T22:01:56Z",
  "published" : "2026-07-20T22:01:56Z",
  "aliases" : [ "CVE-2026-14620" ],
  "summary" : "webpack-dev-server vulnerable to cross-site request forgery via internal developer endpoints",
  "details" : "### Impact\n\nThe internal `/webpack-dev-server/open-editor` and `/webpack-dev-server/invalidate` endpoints perform state-changing actions on any `GET` request, without verifying that the request originated from the dev server's own page. Any website a developer visits while the dev server is running can trigger them cross-origin with no interaction beyond the visit.\n\nAn attacker can open an arbitrary existing local file in the developer's editor, including files outside the project root (e.g. `~/.ssh/config`). The file's contents are not returned to the attacker. Repeated requests can also spawn editor processes and force recompilations, degrading the developer's machine.\n\n### Patches\n\nFixed in `webpack-dev-server` 5.2.6 by rejecting cross-site requests to the `/webpack-dev-server/open-editor` and `/webpack-dev-server/invalidate` endpoints (see [PR #5698](https://github.com/webpack/webpack-dev-server/pull/5698)).\n\n### Workarounds\n\nNone",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "webpack-dev-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.2.6"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.2.5"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-f5vj-f2hx-8m93"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-14620"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/webpack/webpack-dev-server/pull/5698"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/webpack/webpack-dev-server/commit/80cd9eea54975fe632a518d8bd902a260f374e7c"
  }, {
    "type" : "WEB",
    "url" : "https://cna.openjsf.org/security-advisories.html"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/webpack/webpack-dev-server"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/webpack/webpack-dev-server/releases/tag/v5.2.6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-352", "CWE-749" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-20T22:01:56Z",
    "nvd_published_at" : "2026-07-03T17:16:53Z"
  }
}