What is CVE-2026-49452?

CVE-2026-49452 is a medium-severity vulnerability in Kozea Weasyprint, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 6.5/10. Published 2026-08-18.

How severe is CVE-2026-49452?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Kozea Weasyprint

CVE-2026-49452

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.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Kozea Weasyprint — versions < 69.0

Weakness classification (CWE)

CWE-74 — Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

References

security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-49452?: CVE-2026-49452 is a medium-severity vulnerability in Kozea Weasyprint, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 6.5/10. Published 2026-08-18.
How severe is CVE-2026-49452?: Medium severity. CVSS v3 base score is 6.5 out of 10.