How severe is CVE-2026-14620?

CVE-2026-14620 has a CVSS score of 4.7/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-14620?

CVE-2026-14620 affects the following packages: webpack-dev-server (npm). Ecosystems affected: npm.

How do I fix CVE-2026-14620?

Update webpack-dev-server to 5.2.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-14620 is resolved across your whole dependency graph.

How do I detect CVE-2026-14620 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for webpack-dev-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-14620 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-14620 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2026-14620, including 1 documented proof-of-concept exploit on Exploit-DB. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2026-14620?

CVE-2026-14620 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 43th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-14620?

CVE-2026-14620 is classified as Cross-Site Request Forgery (CSRF) (CWE-352), CWE-749 (CWE-749). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-14620 published, and has it been updated?

CVE-2026-14620 was published on July 3, 2026 and was last updated on September 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

CVE-2026-14620 — webpack-dev-server

MEDIUMFix: webpack/webpack-dev-server#5698

CVE-2026-14620 is a medium-severity (CVSS 4.7) Cross-Site Request Forgery (CSRF) vulnerability in webpack-dev-server. 1 public exploit reference exists, so weaponization risk is real. A fix is available for webpack-dev-server — see the affected versions and patch details below.

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

Also known asGHSA-f5vj-f2hx-8m93

Published

Jul 3, 2026

Updated

Sep 4, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Oct 14, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-14620.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs43th percentile — riskier than 43% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-14620 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 388,997 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

12Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

webpack-dev-servernpm

16.7Mdownloads / week

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

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`webpack-dev-server`	all versions	5.2.6`npm install webpack-dev-server@5.2.6`

Affected Products

1 product · 1 configurations

Application

webpack-dev-serverwebpack.js

< 5.2.6

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-52649webappsmultiple

webpack_devserver 5.2.5 - CSRF

by Jorge González Milla · Aug 17, 2026

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for webpack-dev-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update webpack-dev-server to 5.2.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-14620 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Source: Red Hat security advisory for CVE-2026-14620 (CC BY 4.0)

Frequently Asked Questions

### 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 spaw