CVE-2026-49825

lxml: javascript: URL bypass in Cleaner via xlink:href

Published: Aug 20, 2026Updated: Sep 18, 2026 Sources: CVE List NVDCWE-79

8.2HIGH

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:RUser Interaction

Required

Scope

S:CScope

Changed

Impact

C:HConfidentiality

High

I:LIntegrity

Low

A:NAvailability

None

Open in CVSS calculator →

Weaknesses

CWE-79 CWE-184

Affected Products

lxml

oss-projectaka lxml/lxml

lxmlLibrary

OSS Libraries / generic-library

fedora-python

oss-project

lxml_html_cleanLibrary

OSS Libraries / pypi

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Is your org exposed to CVE-2026-49825?Request an assessment to establish which checks are appropriate for your systems. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

2 techniques

Execution

Initial Access

View detailed technique mapping

References

https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-4jhm-jv67-739f

github.com

https://github.com/fedora-python/lxml_html_clean/commit/322357ac61c6cf80fcbaba53b4e92e31f3ded9f2

github.com

https://github.com/lxml/lxml/commit/5927a6d5e851845140975d99b65461e255caaab0

github.com

and 2 more references View all →

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-49825 and every CVE in our database. Create a free account — no credit card required.

Create Free Account

Plain-language analysis

Impact assessment and exploitation scenario in plain English

Attack graph visualization

Interactive attack path and kill chain mapping

Exploit details & PoC links

ExploitDB, Metasploit, GitHub PoCs with direct links

Nuclei scanner templates

Ready-to-use vulnerability scanner templates

Full remediation guide

Patch instructions, workarounds, and compliance impact

Interactive AI chat

Ask questions about this vulnerability in natural language

Related vulnerabilities

Semantically similar CVEs and attack patterns

REST API & MCP access

Integrate vulnerability data into your workflows