Debian Security Advisory

DLA-2606-1 lxml -- LTS security update

Date Reported:
24 Mar 2021
Affected Packages:
Security database references:
In Mitre's CVE dictionary: CVE-2021-28957.
More information:

An issue has been found in lxml, a pythonic binding for the libxml2 and libxslt libraries.

Due to missing input sanitization, XSS is possible for the HTML5 formaction attribute.

For Debian 9 stretch, this problem has been fixed in version 3.7.1-1+deb9u4.

We recommend that you upgrade your lxml packages.

For the detailed security status of lxml please refer to its security tracker page at:

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: