{"id":"EUVD-2026-42327","enisaUuid":"997a477d-be80-3446-a92a-26c86f2a1d16","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.","datePublished":"Jul 8, 2026, 4:09:51 PM","dateUpdated":"Jul 8, 2026, 7:41:04 PM","baseScore":6.1,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","references":"https://github.com/honojs/hono/security/advisories/GHSA-w62v-xxxg-mg59\nhttps://github.com/honojs/hono/commit/cd3f6f7194f0e5c9d4b26ae0cf232018d0f388fc\nhttps://github.com/honojs/hono/releases/tag/v4.12.27\n","aliases":"CVE-2026-59895\nGHSA-w62v-xxxg-mg59\n","assigner":"GitHub_M","epss":0.33,"enisaIdProduct":[{"id":"3b8b3dc5-aea9-3400-82bb-fcec7d4e73df","product":{"name":"hono","vendor":{"name":"honojs"}},"product_version":"4.0.0, \u003c 4.12.27"}],"enisaIdVendor":[{"id":"d995fa46-d47f-3ab7-8c06-1cf496668b6c","vendor":{"name":"honojs"}}],"enisaIdVulnerability":[{"id":"338c78a6-b687-3b14-a6fb-1a20611bf7ca","vulnerability":{"id":"GHSA-w62v-xxxg-mg59","description":"Hono: Server-Side XSS via JSX Escaping Bypass in cx() Utility","datePublished":"Jul 21, 2026, 6:33:50 PM","dateUpdated":"Jul 21, 2026, 6:33:50 PM","baseScore":0.0,"references":"https://github.com/honojs/hono/security/advisories/GHSA-w62v-xxxg-mg59\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-59895\nhttps://github.com/honojs/hono/commit/cd3f6f7194f0e5c9d4b26ae0cf232018d0f388fc\nhttps://github.com/honojs/hono\nhttps://github.com/honojs/hono/releases/tag/v4.12.27\n","enisa_id":"EUVD-2026-42327\n","aliases":"GHSA-w62v-xxxg-mg59\nCVE-2026-59895\n","epss":0.0,"dataProcessed":"Nov 1, 2026, 2:03:08 AM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}},{"id":"f79cb077-d1c3-3c70-b303-f99531f61665","vulnerability":{"id":"CVE-2026-59895","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.","datePublished":"Jul 8, 2026, 4:09:51 PM","dateUpdated":"Jul 8, 2026, 7:41:04 PM","status":"PUBLISHED","baseScore":6.1,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","references":"https://github.com/honojs/hono/security/advisories/GHSA-w62v-xxxg-mg59\nhttps://github.com/honojs/hono/commit/cd3f6f7194f0e5c9d4b26ae0cf232018d0f388fc\nhttps://github.com/honojs/hono/releases/tag/v4.12.27\n","enisa_id":"EUVD-2026-42327\n","assigner":"GitHub_M","epss":0.33,"dataProcessed":"Nov 5, 2026, 7:17:53 AM","vulnerabilityProduct":[{"id":"6e684cd8-7b1e-3de7-9fa6-a9fa047a695e","product":{"name":"hono","vendor":{"name":"honojs"}},"product_version":"4.0.0, \u003c 4.12.27"}],"vulnerabilityVendor":[{"id":"90ca5300-5c42-35ce-9396-28e1093489bb","vendor":{"name":"honojs"}}]}}],"enisaIdAdvisory":[]}