### Impact If an application uses `HttpException::setTitle()` and/or `setDescription()` to include untrusted/request-derived data in the error title or description (e.g. `"No products found matching '{$query}'."`), an attacker could inject arbitrary HTML/JavaScript that executes in the victim's browser when they encounter an HTML error page generated by Slim. The vulnerability is present even with `displayErrorDetails = false` as the unescaped title and description are rendered on this error path. Built-in exceptions (`HttpNotFoundException`, `HttpBadRequestException`, etc.) ship plain-text defaults, so a vanilla Slim app with no user code is not exploitable. Only applications that feed untrusted data into `setTitle()` and/or `setDescription()` are affected. ### Patches The issue is fixed in 4.15.2. ### Workarounds Without upgrading, applications can: - Avoid passing untrusted/request-derived data into `HttpException::setTitle()` and `setDescription()`. Use static, plain-text error copy instead. - Register a custom error renderer (an `ErrorRendererInterface` implementation, or a subclass of `HtmlErrorRenderer` that escapes the title and description) for the HTML media type. ### Acknowledgments Slim is grateful to and thanks GitHub user [0xEr3n](https://github.com/0xEr3n) for reporting this issue. ### Resources - CWE-79: https://cwe.mitre.org/data/definitions/79.html
### Impact If an application uses `HttpException::setTitle()` and/or `setDescription()` to include untrusted/request-derived data in the error title or description (e.g. `"No products found matching '{$query}'."`), an attacker could inject arbitrary HTML/JavaScript that executes in the victim's browser when they encounter an HTML error page generated by Slim. The vulnerability is present even with `displayErrorDetails = false` as the unescaped title and description are rendered on this error path. Built-in exceptions (`HttpNotFoundException`, `HttpBadRequestException`, etc.) ship plain-text defaults, so a vanilla Slim app with no user code is not exploitable. Only applications that feed untrusted data into `setTitle()` and/or `setDescription()` are affected. ### Patches The issue is fixed in 4.15.2. ### Workarounds Without upgrading, applications can: - Avoid passing untrusted/request-derived data into `HttpException::setTitle()` and `setDescription()`. Use static, plain-text error copy instead. - Register a custom error renderer (an `ErrorRendererInterface` implementation, or a subclass of `HtmlErrorRenderer` that escapes the title and description) for the HTML media type. ### Acknowledgments Slim is grateful to and thanks GitHub user [0xEr3n](https://github.com/0xEr3n) for reporting this issue. ### Resources - CWE-79: https://cwe.mitre.org/data/definitions/79.html
Update slim/slim to 4.15.2 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanSlim has Reflected XSS in the HtmlErrorRenderer affects slim/slim (composer). Severity is medium. ### Impact If an application uses `HttpException::setTitle()` and/or `setDescription()` to include untrusted/request-derived data in the error title or description (e.g. `"No products found matching '{$query}'."`), an attacker could inject arbitrary HTML/JavaScript that executes in the victim's browser when they encounter an HTML error page generated by Slim. The vulnerability is present even with `displayErrorDetails = false` as the unescaped title and description are rendered on this error path. Built-in exceptions (`HttpNotFoundException`, `HttpBadRequestException`, etc.) ship plain-text defaults, so a vanilla Slim app with no user code is not exploitable. Only applications that feed untrusted data into `setTitle()` and/or `setDescription()` are affected. ### Patches The issue is fixed in 4.15.2. ### Workarounds Without upgrading, applications can: - Avoid passing untrusted/request-derived data into `HttpException::setTitle()` and `setDescription()`. Use static, plain-text error copy instead. - Register a custom error renderer (an `ErrorRendererInterface` implementation, or a subclass of `HtmlErrorRenderer` that escapes the title and description) for the HTML media type. ### Acknowledgments Slim is grateful to and thanks GitHub user [0xEr3n](https://github.com/0xEr3n) for reporting this issue. ### Resources - CWE-79: https://cwe.mitre.org/data/definitions/79.html
AI coding agents often install or upgrade packages automatically in composer. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| slim/slimcomposer | >=4.4.0,<=4.15.1 | 4.15.2 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate slim/slim to 4.15.2 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanSlim has Reflected XSS in the HtmlErrorRenderer affects slim/slim (composer). Severity is medium. ### Impact If an application uses `HttpException::setTitle()` and/or `setDescription()` to include untrusted/request-derived data in the error title or description (e.g. `"No products found matching '{$query}'."`), an attacker could inject arbitrary HTML/JavaScript that executes in the victim's browser when they encounter an HTML error page generated by Slim. The vulnerability is present even with `displayErrorDetails = false` as the unescaped title and description are rendered on this error path. Built-in exceptions (`HttpNotFoundException`, `HttpBadRequestException`, etc.) ship plain-text defaults, so a vanilla Slim app with no user code is not exploitable. Only applications that feed untrusted data into `setTitle()` and/or `setDescription()` are affected. ### Patches The issue is fixed in 4.15.2. ### Workarounds Without upgrading, applications can: - Avoid passing untrusted/request-derived data into `HttpException::setTitle()` and `setDescription()`. Use static, plain-text error copy instead. - Register a custom error renderer (an `ErrorRendererInterface` implementation, or a subclass of `HtmlErrorRenderer` that escapes the title and description) for the HTML media type. ### Acknowledgments Slim is grateful to and thanks GitHub user [0xEr3n](https://github.com/0xEr3n) for reporting this issue. ### Resources - CWE-79: https://cwe.mitre.org/data/definitions/79.html
AI coding agents often install or upgrade packages automatically in composer. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| slim/slimcomposer | >=4.4.0,<=4.15.1 | 4.15.2 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard