Advisory severityMedium6.1Red Hat Linux

Medium [CVE-2026-59895] Arbitrary markup injection via improper handling of class names in server-side rendering.

This medium-severity Red Hat Linux advisory covers CVE-2026-59895 affecting Migration Toolkit for Applications 8, Red Hat Ansible Automation Platform 2, Red Hat Developer Hub.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-59895 Source published Jul 8, 2026Source updated Jul 8, 2026

VulniPulse record published Jul 28, 2026Record updated Jul 29, 2026

CVE-2026-59895

Affected products & platforms

Red Hat LinuxUnclassified

Open source advisory

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Summary

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.

This could result in Cross-Site Scripting (XSS) attacks, where malicious scripts can be executed in a user's browser. Red Hat severity: Moderate — CVSS 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).

Weakness: CWE-79. Affected Red Hat products: Migration Toolkit for Applications 8; Red Hat Ansible Automation Platform 2; Red Hat Developer Hub; Red Hat OpenShift Dev Spaces.

Red Hat lists Red Hat Hardened Images as not affected. Red Hat does not currently list a fixing RHSA for this CVE.

Affected versions

< 4.0.0
< 4.12.27

Official advisory · high-confidence parse· fetched 12 days ago·verify at source

Fixed versions

4.12.27

Official advisory · high-confidence parse· fetched 12 days ago·verify at source

Mitigation

Upgrade to a fixed release: 4.12.27. That is the remediation for this advisory.

The vendor advisory may list additional interim mitigations or workarounds not captured here — review it before change work.

Official advisory · high-confidence parse· fetched 12 days ago·verify at source

Discussion(0)

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