USN-3841-1: lxml vulnerability

10 December 2018

lxml vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 18.04 LTS
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS


lxml could allow cross-site scripting (XSS) attacks.

Software Description

  • lxml - pythonic binding for the libxml2 and libxslt libraries


It was discovered that lxml incorrectly handled certain HTML files. An attacker could possibly use this issue to conduct cross-site scripting (XSS) attacks.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 18.04 LTS
python-lxml - 4.2.1-1ubuntu0.1
python3-lxml - 4.2.1-1ubuntu0.1
Ubuntu 16.04 LTS
python-lxml - 3.5.0-1ubuntu0.1
python3-lxml - 3.5.0-1ubuntu0.1
Ubuntu 14.04 LTS
python-lxml - 3.3.3-1ubuntu0.2
python3-lxml - 3.3.3-1ubuntu0.2

To update your system, please follow these instructions:

In general, a standard system update will make all the necessary changes.