{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "3.12.0"
                  },
                  {
                    "fixed": "4.13.16"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "fixed": "15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "original_tag": "v4.13.16",
                "range": [
                  {
                    "fixed": "c91b60a251186fb024557c6d55a11d8e388f179c"
                  }
                ],
                "source": "REFERENCES_TAG"
              }
            ]
          },
          "events": [
            {
              "introduced": "3f8d1ea5116dcf81e054f4d6a9b7a4e6ef833cd9"
            },
            {
              "fixed": "c91b60a251186fb024557c6d55a11d8e388f179c"
            },
            {
              "fixed": "15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513"
            }
          ],
          "repo": "https://github.com/honojs/hono",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-3gg2-335m-rxc6"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126359.json"
  },
  "details": "Hono is a Web application framework that provides support for any JavaScript runtime. From 3.12.0 until 4.13.16, the css helper in hono/css escapes interpolated string values separately and therefore fails to neutralize a closing style tag when \u0026lt; ends the template text or a preceding value and / begins the next attacker-controlled value. During server-side rendering, the combined output can close the \u0026lt;Style /\u0026gt; element early and cause the remainder of the interpolated value to be interpreted as HTML. Applications that place an untrusted string immediately after \u0026lt; in a css template, including adjacent untrusted interpolations, can expose viewers to attacker-controlled HTML or script and information accessible to that page. Other uses of the css helper are not affected. This issue is fixed in version 4.13.16.",
  "id": "CVE-2026-126359",
  "modified": "2026-11-14T02:30:46.991518362Z",
  "published": "2026-11-12T22:22:32.161Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/honojs/hono/releases/tag/v4.13.16"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126359.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/honojs/hono/security/advisories/GHSA-3gg2-335m-rxc6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126359"
    },
    {
      "type": "FIX",
      "url": "https://github.com/honojs/hono/commit/15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Hono: `css` helper does not escape a closing tag split between the template and an interpolated value, allowing HTML injection"
}