CVE-2023-50262 is a medium-severity (CVSS 5.3) Improper Input Validation vulnerability in dompdf/dompdf. 1 public exploit reference exists, so weaponization risk is real. A fix is available for dompdf/dompdf — see the affected versions and patch details below.
Dompdf possible DoS caused by infinite recursion when parsing SVG images
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-50262 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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
Summary
When parsing SVG images Dompdf performs an initial validation to ensure that paths within the SVG are allowed. One of the validations is that the SVG document does not reference itself. However, a recursive chained using two or more SVG documents is not correctly validated. Depending on the system configuration and attack pattern this could exhaust the memory available to the executing process and/or to the server itself.
Details
php-svg-lib, when run in isolation, does not support SVG references for image elements. An SVG document can, however, be referenced and Dompdf will run that reference through the same validation. Dompdf currently includes validation to prevent self-referential image references, but a chained reference is not checked. A malicious actor may thus trigger infinite recursion in the validation process by chaining references between two or more SVG images.
PoC
This following sources can be used to bypass validation provided by Dompdf:
recurse.html
<img src="one.svg">
one.svg
<svg width="200" height="200" xmlns="http://www.w3.org/2000/svg">
<image href="two.svg" />
</svg>
two.svg
<svg width="200" height="200" xmlns="http://www.w3.org/2000/svg">
<image href="one.svg" />
</svg>
Impact
When Dompdf parses the above payload, it will crash due after exceeding the allowed execution time or memory usage. An attacker sending multiple request to a system can potentially cause resource exhaustion to the point that the system is unable to handle incoming request.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | dompdf/dompdf | all versions | 2.0.4composer require dompdf/dompdf:^2.0.4 |
Research 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 2.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-50262 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-50262 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-50262. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-50262 in your dependencies?
O3 Security finds CVE-2023-50262 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.