CVE-2026-14631: webpack-dev-server versions 5.2.5 and earlier terminate the whole Node.js process when an unauthenticated peer

Q: How do I fix CVE-2026-14631?

webpack-dev-server: upgrade to 5.2.6. Exact commands for each OS are on this page.

Q: Is CVE-2026-14631 being exploited?

CVE-2026-14631 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-14631 affect?

CVE-2026-14631 affects webpack-dev-server. Severity is medium (CVSS 5.3). 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 malform

Q: How urgent is CVE-2026-14631?

Priority 34/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-14631 is a medium-severity flaw (CVSS 5.3) affecting webpack-dev-server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 cod

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 56%)
CISA exploited list	No
Weakness	CWE-20, CWE-248
Published	2026-07-03
Last modified	2026-07-07

Publisher (CNA): openjs · Vendor: webpack.js

Last updated 2026-07-07 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-03 18:16 UTCPublished CVE record published
2026-07-07 15:08 UTCUpdated Record last modified

webpack.js webpack-dev-server UPGRADE

Affected: < 5.2.6

Fixed in: 5.2.6

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy webpack-dev-server || rpm -q webpack-dev-server || webpack-dev-server --version

2. UPGRADE to 5.2.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade webpack-dev-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade webpack-dev-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-14631?

webpack-dev-server: upgrade to 5.2.6. Exact commands for each OS are on this page.

Is CVE-2026-14631 being exploited?

CVE-2026-14631 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-14631 affect?

CVE-2026-14631 affects webpack-dev-server. Severity is medium (CVSS 5.3). 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 malform

How urgent is CVE-2026-14631?

Priority 34/100. Remotely exploitable, no login, no user action

Software pages

Node.js vulnerabilities · Webpack vulnerabilities

Related CVEs

CVE-2026-14620 MEDIUM 4.7 UPGRADE webpack-dev-server versions 5.2.5 and earlier expose two internal developer endpoints, /webpack-dev-server/ope
CVE-2026-9595 MEDIUM 5.3 UPGRADE Impact: When a user-configured proxy on webpack-dev-server has a broad context (e.g

References

← Back to latest CVEs