[Security] Bump lxml from 4.2.3 to 4.6.3

[dependabot-preview]

Bumps lxml from 4.2.3 to 4.6.3. This update includes security fixes.

Vulnerabilities fixed

Sourced from The GitHub Security Advisory Database.

Cross-Site Scripting in lxml lxml 4.6.2 allows XSS. It places the HTML action attribute into defs.link_attrs (in html/defs.py) for later use in input sanitization, but does not do the same for the HTML5 formaction attribute.

Affected versions: < 4.6.3

Sourced from The GitHub Security Advisory Database.

XSS in lxml A XSS vulnerability was discovered in python-lxml's clean module. The module's parser didn't properly imitate browsers, which caused different behaviors between the sanitizer and the user's page. A remote attacker could exploit this flaw to run arbitrary HTML/JS code.

Affected versions: < 4.6.2

Changelog

Sourced from lxml's changelog.

4.6.3 (2021-03-21)

Bugs fixed

• A vulnerability (CVE-2021-28957) was discovered in the HTML Cleaner by Kevin Chung, which allowed JavaScript to pass through. The cleaner now removes the HTML5 formaction attribute.

4.6.2 (2020-11-26)

Bugs fixed

• A vulnerability (CVE-2020-27783) was discovered in the HTML Cleaner by Yaniv Nizry, which allowed JavaScript to pass through. The cleaner now removes more sneaky "style" content.

4.6.1 (2020-10-18)

Bugs fixed

• A vulnerability was discovered in the HTML Cleaner by Yaniv Nizry, which allowed JavaScript to pass through. The cleaner now removes more sneaky "style" content.

4.6.0 (2020-10-17)

Features added

• GH#310: lxml.html.InputGetter supports __len__() to count the number of input fields. Patch by Aidan Woolley.

• lxml.html.InputGetter has a new .items() method to ease processing all input fields.

• lxml.html.InputGetter.keys() now returns the field names in document order.

• GH-309: The API documentation is now generated using sphinx-apidoc. Patch by Chris Mayo.

Bugs fixed

... (truncated)

Commits

• a5f9cb5 Prepare release of lxml 4.6.3.
• 2d01a1b Add HTML-5 "formaction" attribute to "defs.link_attrs" (GH-316)
• e986a9c Fix reference in docs.
• 4cb5736 Work around Py2's lack of "re.ASCII".
• c30106f Prepare release of 4.6.2.
• a105ab8 Prevent combinations of <math/svg> and <style> to sneak JavaScript through th...
• c053dc1 Add a recipe for a look-ahead generator to allow modifications during tree it...
• b083124 lxml actually works in Py3.9.
• 0f80590 lxml actually works in Py3.9.
• fd8893c Add a doc note that the .find() methods are usually faster than one might exp...
• Additional commits viewable in compare view

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