Vulnerability · Published Sep 19, 2026 · Assigned by VulnCheck

CVE-2026-93981hono/jsx before 4.13.7 Cross-Site Scripting via Unescaped Strings

Medium 4.7

In plain English

A medium-severity cross-site scripting in hono from honojs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.7Medium

Exploit odds (30 days)0.2%top 86.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

hono before 4.13.7 fails to HTML-escape plain strings rendered by hono/jsx as a child or fallback of Suspense, as a string child of ErrorBoundary alongside an asynchronous sibling, as the single child of a Context.Provider, or as the root value passed to renderToString() or renderToReadableStream() from hono/jsx/dom/server. These paths stringify their input and treat the result as already-escaped markup, so an attacker who controls such a string during server-side rendering can inject arbitrary HTML and execute script under the application's origin.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	hono	4.13.7	GHSA-hxh3-vqpv-xpqv

Affected products (as reported)

Vendor	Product	Versions
honojs	hono	0 – before 4.13.7

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-hxh3-vqpv-xpqv) vendor-advisory
VulnCheck Advisory: hono/jsx before 4.13.7 Cross-Site Scripting via Unescaped Strings third-party-advisory