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Fencer Vulns
medium 6.5

CVE-2026-49452 json

WeasyPrint: CSS Injection via Presentational Hints

published 2026-07-06 4 mo ago modified 2026-10-22 17 d ago also EUVD-2026-61143 , GHSA-jhhc-3hcp-qhm5 , PYSEC-2026-3412

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

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.

Patch / fix

  • kozea weasyprint 69.0
  • weasyprint Debian 14 69.0-1

debian advisories DEBIAN-CVE-2026-49452

  • python-weasyprint openSUSE Leap 16.0 65.1-bp160.3.1
  • python-weasyprint openSUSE Tumbleweed 69.0-1.1

opensuse advisories openSUSE-SU-2026:21364-1openSUSE-SU-2026:11249-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-49452 updated cvss 6.5

weasyprint: WeasyPrint: CSS Injection via Presentational Hints

  • Red Hat Ansible Automation Platform 2 ansible-automation-platform/automation-dashboard-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/Kozea/WeasyPrint/security/advisories/GHSA-jhhc-3hcp-qhm5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
pypi weasyprint
<=68.1
 no fix listed

Affected products

  • Kozea WeasyPrint

Classification

Weakness
  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.