Bug 2520368 (CVE-2026-49825)

Summary: CVE-2026-49825 lxml: lxml-html-clean: lxml: URL bypass vulnerability in Cleaner via missing xlink:href
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: akhatavk, alinfoot, amctagga, anthomas, aoconnor, aos-team-art-private, aprice, aruklets, asdas, bniver, cahl, dfreiber, doconnor, dpaolell, dranck, drow, dschmidt, dtrifiro, ebourniv, eglynn, ehelms, flucifre, ggainey, gmeno, groman, hasun, jburrell, jdelft, jjoyce, jlanda, jmitchel, jpasqual, jpretori, jsamir, jschluet, jupierce, juwatts, kaycoth, kshier, lbrazdil, lgarciaa, lhh, ljawale, mbenjamin, mbiarnes, mburns, mdellweg, mgarciac, mhackett, mhulan, mminar, msilmser, nmoumoul, nyancey, oezr, osousa, pakotvan, pcreech, ppalepu, ppostler, prdhamdh, ptisnovs, rbiba, rbryant, rchan, rhel-process-autobot, rjohnson, sbunciak, sghai, sidsharm, simaishi, smallamp, sostapov, sskracic, stcannon, sthirugn, suppawar, teagle, tmalecek, tpfromme, vereddy, vkumar, vlaad, watson-tool-maintainers, weaton, yguenane
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in lxml, a library for processing XML and HTML in Python. The `lxml.html.defs.link_attrs` were missing `xlink:href`, which could allow an attacker to bypass URL filtering mechanisms. This vulnerability enables URL bypass attacks in embedded content such as Scalable Vector Graphics (SVG) or Mathematical Markup Language (MathML), potentially leading to information disclosure or arbitrary code execution in the context of the user's browser.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-20 15:05:11 UTC
lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.1, link attributes in ``lxml.html.defs.link_attrs`` were missing ``xlink:href``, which can be used for URL bypass attacks in embedded SVG/MathML/etc. content. This vulnerability was fixed in lxml 6.1.1 and lxml_html_clean 0.4.5.