Hono: Server-Side XSS via JSX Escaping Bypass in cx() Utility (honojs hono)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.33 % · percentile 26 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD 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.
Weaknesses (CWE)
- CWE-79 — Improper Neutralization of Input During Web Page Generation
- CWE-116 — Improper Encoding or Escaping of Output
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N | GitHub_M |
| CVSS 3.1 | MEDIUM 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-w62v-xxxg-mg59 — Hono: Server-Side XSS via JSX Escaping Bypass in cx() Utility
European references
- ENISA EUVD · EUVD-2026-42327
- GCVE · GCVE-0-2026-59895
Affected configurations (NVD CPE)
cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*≥ 4.0.0 < 4.12.27
Affected products
| Product | Versions |
|---|---|
| honojs · hono | affected >= 4.0.0, < 4.12.27 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |