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webpack-dev-server vulnerable to cross-site request forgery via internal developer endpoints

Moderate severity GitHub Reviewed Published Jul 3, 2026 in webpack/webpack-dev-server • Updated Jul 20, 2026

Package

npm webpack-dev-server (npm)

Affected versions

<= 5.2.5

Patched versions

5.2.6

Description

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).

Workarounds

None

References

@UlisesGascon UlisesGascon published to webpack/webpack-dev-server Jul 3, 2026
Published by the National Vulnerability Database Jul 3, 2026
Published to the GitHub Advisory Database Jul 20, 2026
Reviewed Jul 20, 2026
Last updated Jul 20, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(42nd percentile)

Weaknesses

Cross-Site Request Forgery (CSRF)

The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor. Learn more on MITRE.

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. Learn more on MITRE.

CVE ID

CVE-2026-14620

GHSA ID

GHSA-f5vj-f2hx-8m93

Source code

Credits

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