webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-14631
StatePUBLISHED
Assigneropenjs
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-03 18:16:24 UTC
Updated2026-07-07 15:08:59 UTC
Descriptionwebpack-dev-server versions 5.2.5 and earlier terminate the whole Node.js process when an unauthenticated peer sends either a normal HTTP request with a malformed Host header or a WebSocket upgrade to the default /ws endpoint with a malformed Origin header. The malformed value causes an uncaught exception in the host-validation path and crashes the dev server. Impact is limited to availability of the development server, no data disclosure, no code execution. Patches: upgrade to webpack-dev-server 5.2.6. Workarounds: keep the dev server bound to localhost (the default) and do not expose it to untrusted networks.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from ce714d77-add3-4f53-aff5-83d477b104bb

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS: 0.003080000 probability, percentile 0.225910000 (date 2026-07-06)

Problem Types: CWE-20 | CWE-248 | CWE-20 CWE-20: Improper Input Validation | CWE-248 CWE-248: Uncaught Exception

VersionSourceTypeScoreSeverityVector
3.1ce714d77-add3-4f53-aff5-83d477b104bbSecondary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
3.1CNACVSS5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Webpack.js Webpack-dev-server All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Webpack-dev-server Webpack-dev-server affected 5.2.6 semver Not specified
CNA Webpack-dev-server Webpack-dev-server unaffected 5.2.6 semver Not specified

References

ReferenceSourceLinkTags
github.com/webpack/webpack-dev-server/security/advisories/GHSA-m28w-2pqf... ce714d77-add3-4f53-aff5-83d477b104bb github.com Mitigation, Vendor Advisory, Patch
cna.openjsf.org/security-advisories.html ce714d77-add3-4f53-aff5-83d477b104bb cna.openjsf.org Third Party Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Str1ckl4nd (en)

CNA: bjohansebas (en)

CNA: UlisesGascon (en)

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