{"cve":"CVE-2026-59895","nvd":{"published":"2026-07-08T17:17:27.353","modified":"2026-10-25T17:10:00.197","status":"Analyzed","description":"Hono is a Web application framework that provides support for any JavaScript runtime. From 4.0.0 before 4.12.27, cx() in hono/css composes class names from plain strings but marks the result as already escaped without HTML-escaping the input, allowing untrusted className values used in a JSX class attribute during server-side rendering to break out of the attribute and inject arbitrary markup. This issue is fixed in version 4.12.27.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-79","CWE-116"],"references":["https://github.com/honojs/hono/commit/cd3f6f7194f0e5c9d4b26ae0cf232018d0f388fc","https://github.com/honojs/hono/releases/tag/v4.12.27","https://github.com/honojs/hono/security/advisories/GHSA-w62v-xxxg-mg59"],"products":["hono:hono"],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-59895","score":0.00327,"percentile":0.25545,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-w62v-xxxg-mg59","url":"https://osv.dev/vulnerability/GHSA-w62v-xxxg-mg59","summary":"Hono: Server-Side XSS via JSX Escaping Bypass in cx() Utility","modified":"2026-09-10T03:51:12.371507758Z","packages":[{"ecosystem":"npm","name":"hono","purl":"pkg:npm/hono","ranges":[">=4.0.0 <4.12.27"],"fixed":["4.12.27"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}