# CVE-2019-17020: Firefox ESR: If an XML file is served with a Content Security Policy and the XML file includes an XSL stylesheet,…

CVE-2019-17020 is fixed in 4 products on 2 platforms, first by firefox 72.0.1+build1-0ubuntu0.18.04.1, released January 8, 2020. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2019-17020
- Priority: Routine
- CVSS: 6.5 (Medium)
- EPSS: 0.0114
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jan 8, 2020
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2019-17020

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | Mozilla Firefox ESR (en-US) | 78.0esr | [Mozilla Firefox ESR (en-US) 78.0esr](https://patchblox.com/security/data/fix/windows-app/mozilla.firefox.esr-78.0esr.md) | Jun 25, 2020 |
| Linux | firefox Ubuntu 18.04.6 LTS (bionic) | 72.0.1+build1-0ubuntu0.18.04.1 | [firefox 72.0.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-72.0.1-build1-0ubuntu0.18.04.1.md) | Jan 8, 2020 |
| Linux | firefox Ubuntu 20.04 LTS (focal) | 72.0.1+build1-0ubuntu1 | [firefox 72.0.1+build1-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-72.0.1-build1-0ubuntu1.md) | Jan 8, 2020 |
| Linux | firefox-geckodriver Ubuntu 18.04.6 LTS (bionic) | 72.0.1+build1-0ubuntu0.18.04.1 | [firefox-geckodriver 72.0.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-geckodriver-72.0.1-build1-0ubuntu0.18.04.1.md) | Jan 8, 2020 |
| Linux | firefox-geckodriver Ubuntu 20.04 LTS (focal) | 72.0.1+build1-0ubuntu1 | [firefox-geckodriver 72.0.1+build1-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-geckodriver-72.0.1-build1-0ubuntu1.md) | Jan 8, 2020 |
| Linux | firefox-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 72.0.1+build1-0ubuntu0.18.04.1 | [firefox-mozsymbols 72.0.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-mozsymbols-72.0.1-build1-0ubuntu0.18.04.1.md) | Jan 8, 2020 |
| Linux | firefox-mozsymbols Ubuntu 20.04 LTS (focal) | 72.0.1+build1-0ubuntu1 | [firefox-mozsymbols 72.0.1+build1-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-mozsymbols-72.0.1-build1-0ubuntu1.md) | Jan 8, 2020 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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