Bug 2518129 (CVE-2026-49452)

Summary:	CVE-2026-49452 weasyprint: WeasyPrint: CSS Injection via Presentational Hints
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dschmidt, jlanda, kshier, simaishi, stcannon, teagle, yguenane
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in WeasyPrint, a tool designed to create PDF documents from web content. When processing untrusted HTML with presentational hints enabled, WeasyPrint embeds unescaped HTML attribute values directly into CSS declarations. This vulnerability allows a remote attacker to inject arbitrary CSS, potentially leading to information disclosure or the initiation of server-side requests through specially crafted url() values.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2522064
Bug Blocks:

Description OSIDB Bzimport 2026-08-18 18:21:57 UTC

WeasyPrint helps web developers to create PDF documents. Prior to 69.0, WeasyPrint embeds unescaped HTML presentational-hint attribute values into CSS in weasyprint/css/__init__.py when presentational_hints=True. The background attribute is inserted into a background-image:url() declaration and parsed by tinycss2.parse_blocks_contents(), allowing untrusted HTML to inject additional CSS declarations. Applications that render untrusted HTML with presentational hints enabled can be affected by CSS injection and server-side requests through injected url() values. This issue is fixed in version 69.0.