How severe is CVE-2016-4428?

CVE-2016-4428 has a CVSS score of 5.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2016-4428?

CVE-2016-4428 affects the following packages: horizon (PyPI), horizon (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2016-4428?

Update horizon to 8.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-4428 is resolved across your whole dependency graph.

How do I detect CVE-2016-4428 in my PyPI dependencies?

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

How do I mitigate CVE-2016-4428 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2016-4428 actively exploited in the wild?

No public exploit code has been indexed for CVE-2016-4428 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2016-4428?

CVE-2016-4428 has an EPSS (Exploit Prediction Scoring System) score of 2.1%, placing it in the 82th 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-2016-4428?

CVE-2016-4428 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2016-4428 published, and has it been updated?

CVE-2016-4428 was published on July 12, 2016 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2016-4428 — horizon

MEDIUMFix: openstack/horizon@62b4e6f

CVE-2016-4428 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in horizon. A fix is available for horizon — see the affected versions and patch details below.

OpenStack Dashboard (Horizon) Cross-site scripting (XSS) vulnerability

Also known asGHSA-grm6-x6mr-q3cvPYSEC-2026-643

Published

Jul 12, 2016

Updated

Oct 24, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 1, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs82th percentile — riskier than 82% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

🐍horizon🐍horizon

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Cross-site scripting (XSS) vulnerability in OpenStack Dashboard (Horizon) 8.0.1 and earlier and 9.0.0 through 9.0.1 allows remote authenticated users to inject arbitrary web script or HTML by injecting an AngularJS template in a dashboard form.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`horizon`	all versions	8.0.2`pip install --upgrade 'horizon==8.0.2'`
🐍PyPI	`horizon`	≥ 9.0.0&&< 9.1.0	9.1.0`pip install --upgrade 'horizon==9.1.0'`

Affected Products

3 products · 9 configurations

debian linuxdebian

2 versions

8.09.0

Application

horizonopenstack

≥ 8.0.0 && ≤ 8.0.1

2 versions

9.0.09.0.1

Application

openstackredhat

4 versions

5.06.07.08

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for horizon, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update horizon to 8.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-4428 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

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 HatImportant

Product	Fixed in	Advisory
Red Hat Enterprise Linux OpenStack Platform 5.0 (Icehouse) for RHEL 6	`python-django-horizon-0:2014.1.5-4.el6ost`	RHSA-2016:1268
Red Hat Enterprise Linux OpenStack Platform 5.0 (Icehouse) for RHEL 7	`python-django-horizon-0:2014.1.5-4.el7ost`	RHSA-2016:1269
Red Hat Enterprise Linux OpenStack Platform 6.0 (Juno) for RHEL 7	`python-django-horizon-0:2014.2.3-9.el7ost`	RHSA-2016:1271
Red Hat Enterprise Linux OpenStack Platform 7.0 (Kilo) for RHEL 7	`python-django-horizon-0:2015.1.4-1.el7ost`	RHSA-2016:1272
Red Hat OpenStack Platform 8.0 (Liberty)	`python-django-horizon-1:8.0.1-4.el7ost`	RHSA-2016:1270

UbuntuMEDIUM

USN-3447-1Ubuntu

Frequently Asked Questions

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