CVE-2026-49452
WeasyPrint: CSS Injection via Presentational Hints
- State
- Published
- Severity
- 6.5 Medium
- Published
- Aug 18, 2026
- Updated
- Aug 19, 2026
- Reserved
- May 30, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N | GitHub_M |
Weaknesses
- CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Affected Products
| Product | Versions |
|---|---|
WeasyPrintKozea |
|
References
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