Dompdf allows remote file inclusion because URI validation failure does not halt font registrationGHSA-6x28-7h8c-chx4
HIGHFix: dompdf/dompdf#2995GHSA-6x28-7h8c-chx4 is a high-severity (CVSS 7.5) CWE-552 vulnerability in dompdf/dompdf. 4 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for dompdf/dompdf — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-6x28-7h8c-chx4.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
dompdf/dompdfReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
registerFont in FontMetrics.php in Dompdf before 2.0.1 allows remote file inclusion because a URI validation failure does not halt font registration, as demonstrated by a @font-face rule.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | dompdf/dompdf | all versions | 2.0.1composer require dompdf/dompdf:^2.0.1 |
Affected Products
dompdfdompdf_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dompdf/dompdf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update dompdf/dompdf to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6x28-7h8c-chx4 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is GHSA-6x28-7h8c-chx4 in your dependencies?
Find it across Packagist, including transitive dependencies.