CVE-2019-17020

What it is

If an XML file is served with a Content Security Policy and the XML file includes an XSL stylesheet, the Content Security Policy will not be applied to the contents of the XSL stylesheet. If the XSL sheet e.g. includes JavaScript, it would bypass any of the restrictions of the Content Security Policy applied to the XML document. This vulnerability affects Firefox < 72.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data tampering.

Exploit odds

1.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2020-01-08 22:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 02:23 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.1% in the next 30 days (EPSS).
• Severity: 6.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2020-01-08 22:15 UTC

Last modified

2026-06-17 02:23 UTC

Exploit probability

1.1% · EPSS, next 30 days

Weakness

CWE-611 · XML external entity

Record status

Modified

Affected

• Mozilla Firefox < 72.0
• Canonical Ubuntu Linux 16.04
• Canonical Ubuntu Linux 18.04
• Canonical Ubuntu Linux 19.04
• Canonical Ubuntu Linux 19.10

Attack profile CVSS 3.1 · 6.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2019-17020.md and follow it. Check whether this project is affected by CVE-2019-17020. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge