What is CVE-2026-59895?

CVE-2026-59895 is a medium-severity vulnerability in Honojs Hono, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-07-08.

How severe is CVE-2026-59895?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Honojs Hono

CVE-2026-59895

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 inp…

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Honojs Hono — versions >= 4.0.0, < 4.12.27

Weakness classification (CWE)

CWE-79 — Cross-site Scripting
CWE-116 — Improper Encoding or Escaping of Output

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-59895?: CVE-2026-59895 is a medium-severity vulnerability in Honojs Hono, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-07-08.
How severe is CVE-2026-59895?: Medium severity. CVSS v3 base score is 6.1 out of 10.