# CVE-2018-19787: Improper Neutralization of Input During Web Page Generation in LXML

Source: https://junglewise.ai/threats/cve-2018-19787-improper-neutralization-of-input-during-web-page-generation-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2018-12-02  
License: CC BY 4.0 with a link back

CVE-2018-19787 · Severity: low · CVSS 3 · Published 2018-12-02

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.

Technologies: [lxml (PyPI)](https://junglewise.ai/threats/technologies/lxml). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2018-19787 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2018-19787 being exploited in the wild.

**How severe is CVE-2018-19787?** Low severity, with a CVSS score of 3, published 2 December 2018.

**Which products and versions are affected?** lxml (PyPI) ECOSYSTEM:introduced=0,fixed=4.2.5, GIT:introduced=0,fixed=6be1d081b49c97cfd7b3fbd934a193b668629109|ECOSYSTEM:introduced=0,fixed=4.2.5.

**Is there a fix for CVE-2018-19787?** Yes. lxml (PyPI): upgrade to 4.2.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2018-19787?** Check whether you run lxml (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- lxml (PyPI): upgrade to 4.2.5 or later

  ```sh
  pip install "lxml>=4.2.5"
  ```


## Affected products

- lxml (PyPI) ECOSYSTEM:introduced=0,fixed=4.2.5, GIT:introduced=0,fixed=6be1d081b49c97cfd7b3fbd934a193b668629109|ECOSYSTEM:introduced=0,fixed=4.2.5

## Identifiers

- CVE-2018-19787
- GHSA-xp26-p53h-6h2p
- PYSEC-2018-12

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- [lxml's HTML Cleaner allows crafted and SVG embedded scripts to pass through](https://junglewise.ai/threats/cve-2021-43818-lxml-s-html-cleaner-allows-crafted-and-svg-embedded-scripts-to)
- [lxml vulnerable to Cross-Site Scripting](https://junglewise.ai/threats/cve-2021-28957-lxml-vulnerable-to-cross-site-scripting)
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