What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 4.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-19 · updated 2026-09-21
• Weakness: CWE-79

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 products

• honojs hono: before 4.13.7 — fixed in 4.13.7

How to fix

Upgrade to a fixed version: honojs hono 4.13.7. Check the vendor advisory for mitigations.

References

• https://github.com/honojs/hono/security/advisories/GHSA-hxh3-vqpv-xpqv
• https://www.vulncheck.com/advisories/hono-jsx-before-4.13.7-cross-site-scripting-via-unescaped-strings

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