# CVE-2018-19787: python3-lxml: An issue was discovered in lxml before 4.2.5

CVE-2018-19787 is fixed in 2 products on 1 platform, first by python-lxml 4.2.1-1ubuntu0.1, released December 1, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-19787
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0244
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 1, 2018

## Description

An issue was discovered in lxml before 4.2.5. lxml/html/clean.py in the lxml.html.clean module does not remove javascript: URLs that use escaping, allowing a remote attacker to conduct XSS attacks, as demonstrated by "j a v a s c r i p t:" in Internet Explorer. This is a similar issue to CVE-2014-3146.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-lxml Ubuntu 18.04.6 LTS (bionic) | 4.2.1-1ubuntu0.1 | [python-lxml 4.2.1-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-lxml-4.2.1-1ubuntu0.1.md) | Dec 1, 2018 |
| Linux | python3-lxml Ubuntu 18.04.6 LTS (bionic) | 4.2.1-1ubuntu0.1 | [python3-lxml 4.2.1-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-lxml-4.2.1-1ubuntu0.1.md) | Dec 1, 2018 |

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Data as of 2026-11-07T06:34:28Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo