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CVE-2026-112085

webpack-dev-server vulnerable to cross-origin WebSocket access via proxied upgrades

CVSS score

8.2

EPSS probability

—

Risk score

0.8

Published

3 h ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

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Vulnerability description

DayBreach AI Explanation

Verified against sources

CVE-2026-112085: webpack-dev-server Cross-Origin WebSocket Access Vulnerability

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

webpack-dev-server is vulnerable to cross-origin WebSocket access because it fails to validate Host or Origin headers during proxy upgrades.

Why does it matter?

Attackers can leverage a malicious web page visited by a developer to open a cross-origin WebSocket and interact with the proxied backend.

What should be done?

  • Follow vendor advisory to apply updates
  • Omit WebSocket forwarding from unnecessary proxy entries
  • Scope the proxy to specific paths
Chain of evidence and sources2 verified claims

webpack-dev-server, proxy yönlendirmelerinde Host veya Origin başlıklarını doğrulamamaktadır.

S0 · daybreach-canonicalS1 · cvelist

Kötü amaçlı bir web sayfası üzerinden çapraz kaynaklı WebSocket bağlantısı açılabilmektedir.

S0 · daybreach-canonicalS1 · cvelist
Show the technical text from the sources

webpack-dev-server is a development server that provides live reloading for webpack projects. In versions before 5.2.7 and in version 6.0.0, when a proxy entry is configured to forward WebSockets, the server forwards non-HMR WebSocket upgrade requests to the proxy target without validating the Host or Origin headers, so the allowedHosts protection does not apply to those proxied upgrades. A malicious web page visited by a developer can open a cross-origin WebSocket through the dev server and read from and write to the proxied backend, even when the server is bound to loopback. The issue is fixed in webpack-dev-server 5.2.7 and 6.1.0, where proxied WebSocket upgrades pass the same Host and Origin validation as the HMR WebSocket, and users should upgrade to one of those versions or later. As a workaround, omit WebSocket forwarding from proxy entries that do not need it and scope the proxy to specific paths.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

CWE: CWE-346, CWE-1385

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-112085 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1webpack-dev-serverwebpack-dev-server View
Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
8.2CVSS V3_1HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:NCVE CNA
8.2CVSS V31HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:NNVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-112085 is associated with the following CWEs:

CWE-346: Common Weakness Enumeration Entry CWE-346CWE-1385: Common Weakness Enumeration Entry CWE-1385

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-112085 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekiyor

Official Sources and Advisories

https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-cfqc-fj3v-j925vendor-advisoryhttps://cna.openjsf.org/security-advisories.htmlvendor-advisory

CVSS Vector Radar Chart

8.2 / 10
Attack VectorNetworkComplexityLowPrivilegesNoneUser Interact.RequiredConfidentialityLowIntegrityLowAvailabilityNone

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone required
User Interaction—
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)Low
Availability (Erişilebilirlik)None

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

W
webpack-dev-server logo
webpack-dev-server

Weakness Type (CWE & CAPEC)

CWE-346 CWE-1385

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CVE-2026-112085 · webpack-dev-server vulnerable to…