Upstream information
Description
lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.0, the HTML Parser in lxml does not properly handle context-switching for special HTML tags such as `<svg>`, `<math>` and `<noscript>`. This behavior deviates from how web browsers parse and interpret such tags. Specifically, content in CSS comments is ignored by lxml_html_clean but may be interpreted differently by web browsers, enabling malicious scripts to bypass the cleaning process. This vulnerability could lead to Cross-Site Scripting (XSS) attacks, compromising the security of users relying on lxml_html_clean in default configuration for sanitizing untrusted HTML content. Users employing the HTML cleaner in a security-sensitive context should upgrade to lxml 0.4.0, which addresses this issue. As a temporary mitigation, users can configure lxml_html_clean with the following settings to prevent the exploitation of this vulnerability. Via `remove_tags`, one may specify tags to remove - their content is moved to their parents' tags. Via `kill_tags`, one may specify tags to be removed completely. Via `allow_tags`, one may restrict the set of permissible tags, excluding context-switching tags like `<svg>`, `<math>` and `<noscript>`.SUSE information
Overall state of this security issue: Resolved
This issue is currently rated as having important severity.
| CVSS detail | CNA (GitHub) | National Vulnerability Database |
|---|---|---|
| Base Score | 7.7 | 6.1 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| Attack Vector | Network | Network |
| Attack Complexity | High | Low |
| Privileges Required | None | None |
| User Interaction | None | Required |
| Scope | Unchanged | Changed |
| Confidentiality Impact | High | Low |
| Integrity Impact | Low | Low |
| Availability Impact | High | None |
| CVSSv3 Version | 3.1 | 3.1 |
SUSE Timeline for this CVE
CVE page created: Wed Nov 20 00:02:26 2024CVE page last modified: Mon Oct 6 20:01:33 2025