CVE-2026-49825

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

HIGH
8.2
CVSS Score
Published: August 20, 2026 at 02:42 PM UTC
Updated: October 26, 2026 at 10:10 AM UTC
2 products affected across 2 vendorsLxmlLxml Html Clean

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Severity
HIGH8.2
Exploit prediction
EPSS 0.3%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.4.5
Affected range stops below 0.4.5, so it looks safe — our inference, not a vendor statement
v < 6.1.1
Affected range stops below 6.1.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-79CWE-184

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