{"id":"CVE-2026-48157","title":"Slim has Reflected XSS in the HtmlErrorRenderer","summary":"Slim has Reflected XSS in the HtmlErrorRenderer","severity":"medium","cvss":6.1,"cwe":["CWE-79"],"vendor":"slim","product":"slim/slim","ecosystem":"composer","affected":["slim/slim >= 4.4.0, <= 4.15.1"],"patched":["slim/slim 4.15.2"],"published":"2026-06-23","updated":"2026-06-23","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-53h4-8rc4-f539","references":[{"url":"https://github.com/slimphp/Slim/security/advisories/GHSA-53h4-8rc4-f539"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48157"},{"url":"https://github.com/slimphp/Slim/releases/tag/4.15.2"},{"url":"https://github.com/advisories/GHSA-53h4-8rc4-f539"}],"tags":["ghsa","composer"],"epss":0.00167,"epssPercentile":0.06379,"ingestedAt":"2026-06-26T16:43:14.611Z","slug":"CVE-2026-48157","body":"## Overview\n\n### Impact\n\nIf 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.\n\nThe vulnerability is present even with `displayErrorDetails = false` as the unescaped title and description are rendered on this error path.\n\nBuilt-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.\n\n### Patches\n\nThe issue is fixed in 4.15.2.\n\n### Workarounds\n\nWithout upgrading, applications can:\n\n- Avoid passing untrusted/request-derived data into `HttpException::setTitle()` and `setDescription()`. Use static, plain-text error copy instead.\n- Register a custom error renderer (an `ErrorRendererInterface` implementation, or a subclass of `HtmlErrorRenderer` that escapes the title and description) for the HTML media type.\n\n### Acknowledgments\n\nSlim is grateful to and thanks GitHub user [0xEr3n](https://github.com/0xEr3n) for reporting this issue.\n\n### Resources\n\n- CWE-79: https://cwe.mitre.org/data/definitions/79.html\n\n## Affected packages\n\n- `slim/slim >= 4.4.0, <= 4.15.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `slim/slim 4.15.2`","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":33.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}