Bug 2444963 (CVE-2026-28350)

Summary: CVE-2026-28350 lxml_html_clean: lxml_html_clean: Web link hijacking due to improper base tag handling
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in lxml_html_clean. This vulnerability allows a remote attacker to inject a `<base>` tag into a web page. Due to improper handling of HTML cleaning configurations, an attacker can hijack relative links on the page, potentially leading to information disclosure or redirection of web traffic.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2444971    
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Description OSIDB Bzimport 2026-03-05 21:01:59 UTC
lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.4, the <base> tag passes through the default Cleaner configuration. While page_structure=True removes html, head, and title tags, there is no specific handling for <base>, allowing an attacker to inject it and hijack relative links on the page. This issue has been patched in version 0.4.4.