How severe is CVE-2023-28447?

CVE-2023-28447 has a CVSS score of 7.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-28447?

CVE-2023-28447 affects the following packages: smarty/smarty (Packagist), smarty/smarty (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2023-28447?

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.

How do I detect CVE-2023-28447 in my Packagist dependencies?

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.

How do I mitigate CVE-2023-28447 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2023-28447 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-28447 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-28447?

CVE-2023-28447 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 63th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-28447?

CVE-2023-28447 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2023-28447 published, and has it been updated?

CVE-2023-28447 was published on March 28, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2023-28447: smarty — Fixed in 4.3.1

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs63th percentile — riskier than 63% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

🐘smarty/smarty🐘smarty/smarty

Real-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

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`smarty/smarty`	≥ 4.0.0&&< 4.3.1	4.3.1`composer require smarty/smarty:^4.3.1`
🐘Packagist	`smarty/smarty`	all versions	3.1.48`composer require smarty/smarty:^3.1.48`

Affected Products

2 products · 5 configurations

OS

fedorafedoraproject

3 versions

363738

Application

smartysmarty

≥ 4.0.0 && < 4.3.1

range

Detection & mitigation playbook

Open-source dependency

Detect
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
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

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CVE-2023-28447 — smarty

EPSS Exploitation Probability

How urgent is this, really

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