CVE-2026-44458: CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') in honojs hono
CVE-2026-44458 is a medium severity vulnerability in the honojs hono web application framework prior to version 4. 12. 18. The issue involves improper neutralization of special elements in CSS style attribute values rendered by the JSX renderer. Specifically, untrusted input in style object values or property names can inject additional CSS declarations into the rendered style attribute. This vulnerability affects only CSS injection and does not allow JavaScript execution or HTML attribute breakout. The vulnerability is fixed in version 4. 12. 18.
AI Analysis
Technical Summary
The honojs hono framework versions before 4.12.18 have a vulnerability where the JSX renderer escapes style attribute object values for HTML but not for CSS. This allows untrusted input in style object values or property names to inject additional CSS declarations into the rendered style attribute. The vulnerability is categorized under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component) and CWE-116. The impact is limited to CSS injection without enabling JavaScript execution or HTML attribute breakout. The issue is resolved in version 4.12.18.
Potential Impact
The vulnerability allows an attacker to inject arbitrary CSS declarations via untrusted input in style object values or property names. This can affect the visual rendering of the web application but does not permit execution of JavaScript or breaking out of HTML attributes. The CVSS score is 4.3 (medium severity), reflecting limited impact confined to CSS injection.
Mitigation Recommendations
Upgrade the honojs hono framework to version 4.12.18 or later, where this vulnerability is fixed. No other mitigation is indicated or required as the fix is available in the official release.
CVE-2026-44458: CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') in honojs hono
Description
CVE-2026-44458 is a medium severity vulnerability in the honojs hono web application framework prior to version 4. 12. 18. The issue involves improper neutralization of special elements in CSS style attribute values rendered by the JSX renderer. Specifically, untrusted input in style object values or property names can inject additional CSS declarations into the rendered style attribute. This vulnerability affects only CSS injection and does not allow JavaScript execution or HTML attribute breakout. The vulnerability is fixed in version 4. 12. 18.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The honojs hono framework versions before 4.12.18 have a vulnerability where the JSX renderer escapes style attribute object values for HTML but not for CSS. This allows untrusted input in style object values or property names to inject additional CSS declarations into the rendered style attribute. The vulnerability is categorized under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component) and CWE-116. The impact is limited to CSS injection without enabling JavaScript execution or HTML attribute breakout. The issue is resolved in version 4.12.18.
Potential Impact
The vulnerability allows an attacker to inject arbitrary CSS declarations via untrusted input in style object values or property names. This can affect the visual rendering of the web application but does not permit execution of JavaScript or breaking out of HTML attributes. The CVSS score is 4.3 (medium severity), reflecting limited impact confined to CSS injection.
Mitigation Recommendations
Upgrade the honojs hono framework to version 4.12.18 or later, where this vulnerability is fixed. No other mitigation is indicated or required as the fix is available in the official release.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-06T15:49:25.193Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a049721cbff5d8610e00edb
Added to database: 5/13/2026, 3:22:09 PM
Last enriched: 5/13/2026, 3:37:48 PM
Last updated: 5/13/2026, 6:31:59 PM
Views: 4
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