CVE-2026-42548
High
Description
Flight is an extensible micro-framework for PHP. Prior to 3.18.1, Flight::jsonp() concatenates the ?jsonp= query parameter directly into an application/javascript response body without validating that the value is a legal JavaScript identifier. An attacker can inject arbitrary JavaScript that executes in the response origin, enabling reflected cross-site scripting. This vulnerability is fixed in 3.18.1.
SeverityHigh
CVSS8.6
Exploit probability—
ProductFlightphp/core
PublishedMay 13, 2026
First seenMay 13, 2026
Weakness typeCWE-79Cross-site scripting (XSS)
How to fix
Update
- flightphp/core3.18.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| flightphp/corePackagist | v < 3.18.1 | 3.18.1 |
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