5.3

CVE-2026-14631: webpack-dev-server Improper Input Validation

CVSS: 5.3v3.1MediumAnalyzed
AliasesCGA-4w5c-c2fm-2mw9CGA-vx88-pqmh-2x55GHSA-m28w-2pqf-7qgj
Published 03-07-2026Last modified 06-07-2026
Open JSON

Vulnerability summary

CVE-2026-14631 is a medium (CVSS 5.3) Improper Input Validation vulnerability in webpack-dev-server. EPSS estimates a 0.52% chance of exploitation in the next 30 days, higher than 42.8% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.52%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-2GVM-FGV4-VVXG

Timeline

  1. 03-07-2026
    PublishedVulnerability first disclosed.
  2. 06-07-2026
    Last modifiedVulnerability information updated.

Description

webpack-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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.52%

Chance of exploitation in the next 30 days

Percentile

43%

Versus all other CVEs

30-day change

0.00 pp

From 0.52% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.52%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard25 products
  • arangodb-3.11< 3.11.14.5-r25
  • arangodb-3.12< 3.12.11-r0
  • argo-workflows-ui-4.0< 4.0.11-r0
  • gitlab-rails-ce-18.1All versions (No fix recorded)
  • gitlab-rails-ce-18.10All versions (No fix recorded)
Npm1 product
  • webpack-dev-server< 5.2.6
Webpack-dev-server1 product
Webpack.js1 product
Wolfi1 product
  • argo-workflows-ui-4.0< 4.0.11-r0

5 vendors · 29 products

References

7 links