High severity · published Aug 20, 2026
CVE-2026-49825
lxml: javascript: URL bypass in Cleaner via xlink:href
8.2
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LX
lxml · lxml
< 6.1.1 · source: vendor
LX
lxml_html_clean · fedora-python
< 0.4.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-49825
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-49825
github.com
https://github.com/fedora-python/lxml_html_clean/commit/322357ac61c6cf80fcbaba53b4e92e31f3ded9f2
github.com
https://github.com/fedora-python/lxml_html_clean/releases/tag/0.4.5
github.com
https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-4jhm-jv67-739f
github.com
https://github.com/lxml/lxml/commit/5927a6d5e851845140975d99b65461e255caaab0
github.com
https://github.com/lxml/lxml/releases/tag/lxml-6.1.1
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