{"id":"CVE-2026-59895","sourceIdentifier":"security-advisories@github.com","published":"2026-07-08T17:17:27.353","lastModified":"2026-07-10T19:53:22.957","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"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."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"honojs","product":"hono","versions":[{"version":">= 4.0.0, < 4.12.27","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","baseScore":6.1,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":2.8,"impactScore":2.7}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-07-08T17:50:18.277447Z","id":"CVE-2026-59895","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-79"},{"lang":"en","value":"CWE-116"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*","versionStartIncluding":"4.0.0","versionEndExcluding":"4.12.27","matchCriteriaId":"08C4DBB0-9F35-4FF1-8BAF-CACAABAD6057"}]}]}],"references":[{"url":"https://github.com/honojs/hono/commit/cd3f6f7194f0e5c9d4b26ae0cf232018d0f388fc","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/honojs/hono/releases/tag/v4.12.27","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/honojs/hono/security/advisories/GHSA-w62v-xxxg-mg59","source":"security-advisories@github.com","tags":["Vendor Advisory"]}]}