CVE-2026-76844Public exploitNetwork attack vectorHinoki check available

Local file disclosure via fixed-offset publicPath slice

Published Aug 24, 2026 · Updated Aug 24, 2026

Path traversal in webpack-dev-middleware allows remote attackers to read files one directory above the configured output path. In getFilenameFromUrl, a prefix-only publicPath check is followed by a fixed-offset slice that turns an embedded '..' suffix into a parent-directory path. Exposure requires a non-slash-terminated publicPath and a physical or custom output filesystem; the default 'auto' publicPath and memfs-backed setup are unaffected.

CVSS severity8.3
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Path traversal in webpack-dev-middleware allows remote attackers to read files one directory above the configured output path. In getFilenameFromUrl, a prefix-only publicPath check is followed by a fixed-offset slice that turns an embedded '..' suffix into a parent-directory path. Exposure requires a non-slash-terminated publicPath and a physical or custom output filesystem; the default 'auto' publicPath and memfs-backed setup are unaffected.

The record

CVE
CVE-2026-76844
Published
Aug 24, 2026
Updated
Aug 24, 2026
Vendor
webpack
Product
webpack-dev-middleware
Classifications
CWE-22, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.3.4 <=5.3.4
  2. Affected versionversion=6.1.2 <=6.1.3
  3. Affected versionversion=7.1.0 <=7.4.5
  4. Affected versionversion=8.0.0 <=8.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

webpack · webpack-dev-middlewareversion=5.3.4 <=5.3.4; version=6.1.2 <=6.1.3; version=7.1.0 <=7.4.5; version=8.0.0 <=8.1.1

Published CVSS scores

8.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo