CVE-2023-28447 is a high-severity (CVSS 7.1) Cross-site Scripting (XSS) vulnerability in smarty/smarty. A fix is available for smarty/smarty — see the affected versions and patch details below.
Cross site scripting vulnerability in Javascript escaping in smarty/smarty
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-2023-28447 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 377,238 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
smarty/smarty🐘smarty/smartyReal-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
Smarty is a template engine for PHP. In affected versions smarty did not properly escape javascript code. An attacker could exploit this vulnerability to execute arbitrary JavaScript code in the context of the user's browser session. This may lead to unauthorized access to sensitive user data, manipulation of the web application's behavior, or unauthorized actions performed on behalf of the user. Users are advised to upgrade to either version 3.1.48 or to 4.3.1 to resolve this issue. There are no known workarounds for this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | smarty/smarty | ≥ 4.0.0&&< 4.3.1 | 4.3.1composer require smarty/smarty:^4.3.1 |
| 🐘Packagist | smarty/smarty | all versions | 3.1.48composer require smarty/smarty:^3.1.48 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for smarty/smarty, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update smarty/smarty to 4.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28447 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-2023-28447 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-28447. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is CVE-2023-28447 in your dependencies?
O3 Security finds CVE-2023-28447 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.